diff --git a/mobile/src/components/pr-sidebar/PRCommentCard.tsx b/mobile/src/components/pr-sidebar/PRCommentCard.tsx
index 4f5d186c7e4..ce1ef33cb96 100644
--- a/mobile/src/components/pr-sidebar/PRCommentCard.tsx
+++ b/mobile/src/components/pr-sidebar/PRCommentCard.tsx
@@ -10,7 +10,7 @@ import { PRCommentComposer } from './PRCommentComposer'
 import { formatPrCommentRelativeTime } from './pr-comment-time'
 import { prCommentsStyles as styles } from './pr-comments-styles'
 
-export type PRCommentRepoSlug = { owner: string; repo: string }
+export type PRCommentRepoSlug = { owner: string; repo: string; host?: string }
 
 // Action handlers are passed from the comment actions hook (stable callbacks), so
 // adding them keeps the memo'd card from re-rendering on unrelated timeline changes.
diff --git a/mobile/src/session/github-pr-mutations.ts b/mobile/src/session/github-pr-mutations.ts
index dff1775f34d..6d615150ad3 100644
--- a/mobile/src/session/github-pr-mutations.ts
+++ b/mobile/src/session/github-pr-mutations.ts
@@ -292,11 +292,10 @@ export async function fetchResolveReviewThread(
 // GitHubProjectMutationResult `{ ok }` envelope sendGithubPrMutation reads.
 export async function fetchUpdateIssueComment(
   client: Pick<RpcClient, 'sendRequest'>,
-  args: { owner: string; repo: string; commentId: number; body: string }
+  args: { owner: string; repo: string; host?: string; commentId: number; body: string }
 ): Promise<GitHubPrMutationOutcome> {
   return sendGithubPrMutation(client, 'github.project.updateIssueCommentBySlug', {
-    owner: args.owner,
-    repo: args.repo,
+    ...githubPrRepoSlugParam(args),
     commentId: args.commentId,
     body: args.body
   })
@@ -305,11 +304,10 @@ export async function fetchUpdateIssueComment(
 // Delete a root conversation (issue) comment. Slug-addressed like the edit wrapper.
 export async function fetchDeleteIssueComment(
   client: Pick<RpcClient, 'sendRequest'>,
-  args: { owner: string; repo: string; commentId: number }
+  args: { owner: string; repo: string; host?: string; commentId: number }
 ): Promise<GitHubPrMutationOutcome> {
   return sendGithubPrMutation(client, 'github.project.deleteIssueCommentBySlug', {
-    owner: args.owner,
-    repo: args.repo,
+    ...githubPrRepoSlugParam(args),
     commentId: args.commentId
   })
 }
diff --git a/mobile/src/session/github-pr-rpc.ts b/mobile/src/session/github-pr-rpc.ts
index e24c50e8dfc..46d6ec2b6a7 100644
--- a/mobile/src/session/github-pr-rpc.ts
+++ b/mobile/src/session/github-pr-rpc.ts
@@ -113,7 +113,10 @@ export async function fetchGithubRepoSlug(
       const record = value as Record<string, unknown>
       const owner = record.owner
       const repo = record.repo
-      return typeof owner === 'string' && typeof repo === 'string' ? { owner, repo } : null
+      const host = record.host
+      return typeof owner === 'string' && typeof repo === 'string'
+        ? { owner, repo, ...(typeof host === 'string' && host ? { host } : {}) }
+        : null
     }
   )
 }
diff --git a/mobile/src/session/pr-comment-actions.ts b/mobile/src/session/pr-comment-actions.ts
index 195d2480d87..012500c62da 100644
--- a/mobile/src/session/pr-comment-actions.ts
+++ b/mobile/src/session/pr-comment-actions.ts
@@ -1,4 +1,4 @@
-import type { PRComment, PRState } from '../../../src/shared/types'
+import type { GitHubOwnerRepo, PRComment, PRState } from '../../../src/shared/types'
 
 // Pure helpers for the interactive PR comment timeline (reply / resolve / add
 // root comment). Kept free of React/native imports so they unit-test under the
@@ -87,35 +87,46 @@ export function isMutablePRConversationComment(
 // can hide the affordance rather than firing a doomed request.
 export function canEditComment(
   comment: Pick<PRComment, 'id' | 'threadId' | 'path' | 'url'>,
-  prRepo: { owner: string; repo: string } | null | undefined
+  prRepo: GitHubOwnerRepo | null | undefined
 ): boolean {
   return Boolean(prRepo) && isMutablePRConversationComment(comment)
 }
 
 export function canDeleteComment(
   comment: Pick<PRComment, 'id' | 'threadId' | 'path' | 'url'>,
-  prRepo: { owner: string; repo: string } | null | undefined
+  prRepo: GitHubOwnerRepo | null | undefined
 ): boolean {
   return Boolean(prRepo) && isMutablePRConversationComment(comment)
 }
 
-export type EditCommentParams = { owner: string; repo: string; commentId: number; body: string }
+export type EditCommentParams = GitHubOwnerRepo & { commentId: number; body: string }
 
 export function buildEditCommentParams(
-  prRepo: { owner: string; repo: string },
+  prRepo: GitHubOwnerRepo,
   commentId: number,
   body: string
 ): EditCommentParams {
-  return { owner: prRepo.owner, repo: prRepo.repo, commentId, body }
+  return {
+    owner: prRepo.owner,
+    repo: prRepo.repo,
+    ...(prRepo.host ? { host: prRepo.host } : {}),
+    commentId,
+    body
+  }
 }
 
-export type DeleteCommentParams = { owner: string; repo: string; commentId: number }
+export type DeleteCommentParams = GitHubOwnerRepo & { commentId: number }
 
 export function buildDeleteCommentParams(
-  prRepo: { owner: string; repo: string },
+  prRepo: GitHubOwnerRepo,
   commentId: number
 ): DeleteCommentParams {
-  return { owner: prRepo.owner, repo: prRepo.repo, commentId }
+  return {
+    owner: prRepo.owner,
+    repo: prRepo.repo,
+    ...(prRepo.host ? { host: prRepo.host } : {}),
+    commentId
+  }
 }
 
 // The composer disables submit on empty/whitespace input (host rejects empty body).
diff --git a/mobile/src/session/use-mobile-pr-comment-actions.ts b/mobile/src/session/use-mobile-pr-comment-actions.ts
index f0909b9e03a..b1eb51ad6ed 100644
--- a/mobile/src/session/use-mobile-pr-comment-actions.ts
+++ b/mobile/src/session/use-mobile-pr-comment-actions.ts
@@ -39,12 +39,14 @@ export type PrCommentMutations = {
   editComment: (args: {
     owner: string
     repo: string
+    host?: string
     commentId: number
     body: string
   }) => Promise<GitHubPrMutationOutcome>
   deleteComment: (args: {
     owner: string
     repo: string
+    host?: string
     commentId: number
   }) => Promise<GitHubPrMutationOutcome>
 }
diff --git a/src/main/github/client.test.ts b/src/main/github/client.test.ts
index 4edf692fa17..860e499d7cf 100644
--- a/src/main/github/client.test.ts
+++ b/src/main/github/client.test.ts
@@ -3625,7 +3625,9 @@ describe('getPRForBranch', () => {
     await expect(getRepoUpstream('/repo-root')).resolves.toBeNull()
 
     expect(ghExecFileAsyncMock).toHaveBeenCalledWith(
-      ['repo', 'view', 'StablyAI/Orca', '--json', 'isFork,parent'],
+      // Why: positional slugs are explicit about github.com too, so GH_HOST
+      // cannot redirect them.
+      ['repo', 'view', 'github.com/StablyAI/Orca', '--json', 'isFork,parent'],
       { cwd: '/repo-root', host: 'github.com', timeout: 10_000 }
     )
   })
diff --git a/src/main/github/client.ts b/src/main/github/client.ts
index 1f3d5d10b92..c73230f323f 100644
--- a/src/main/github/client.ts
+++ b/src/main/github/client.ts
@@ -1477,11 +1477,8 @@ async function countWorkItemsForQuery(
 }
 
 function sameOwnerRepo(left: OwnerRepo | null, right: OwnerRepo | null): boolean {
-  // Why: GitHub owner/repo names are case-insensitive, so differently-cased remotes are the same repo (don't split into two searches).
-  return (
-    left?.owner.toLowerCase() === right?.owner.toLowerCase() &&
-    left?.repo.toLowerCase() === right?.repo.toLowerCase()
-  )
+  // Why: casing does not distinguish GitHub repos, but the same slug on different hosts does.
+  return Boolean(left && right && githubRepoIdentityKey(left) === githubRepoIdentityKey(right))
 }
 
 function defaultOpenWorkItemQuery(): ParsedTaskQuery {
@@ -2911,6 +2908,11 @@ export async function getPRForBranchOutcome(
       connectionId,
       localGitOptions
     )
+    // Why: connection-backed gh runs without a repository cwd. A bare lookup
+    // here can honor process GH_REPO/GH_HOST and return an unrelated PR.
+    if (connectionId && candidates.length === 0) {
+      return { kind: 'no-pr', fetchedAt: Date.now() }
+    }
     let data: PullRequestLookupData | null = null
     let dataRepo: OwnerRepo | null = null
     let dataHeadRepo: OwnerRepo | null = headRepo
diff --git a/src/main/github/github-api-repository.ts b/src/main/github/github-api-repository.ts
index 83a1ce0f716..046001168e6 100644
--- a/src/main/github/github-api-repository.ts
+++ b/src/main/github/github-api-repository.ts
@@ -15,6 +15,7 @@ export type GitHubApiRepository = GitHubOwnerRepo
 // round trip on connection-backed repos) — hot paths like per-file contents
 // and viewed-state toggles resolve per call, so cache like ownerRepoCache does.
 const ORIGIN_REPO_CACHE_TTL_MS = 30_000
+const ORIGIN_REPO_CACHE_MAX_ENTRIES = 512
 const originRepoCache = new Map<string, { value: GitHubApiRepository | null; expiresAt: number }>()
 const originRepoInFlight = new Map<string, Promise<GitHubApiRepository | null>>()
 
@@ -33,6 +34,26 @@ export function _resetOriginGitHubApiRepositoryCache(): void {
   originRepoInFlight.clear()
 }
 
+/** @internal - exposed for cache-bound tests only */
+export function _getOriginGitHubApiRepositoryCacheSize(): number {
+  return originRepoCache.size
+}
+
+function pruneOriginRepoCache(now: number): void {
+  for (const [key, entry] of originRepoCache) {
+    if (entry.expiresAt <= now) {
+      originRepoCache.delete(key)
+    }
+  }
+  while (originRepoCache.size > ORIGIN_REPO_CACHE_MAX_ENTRIES) {
+    const oldestKey = originRepoCache.keys().next().value
+    if (oldestKey === undefined) {
+      return
+    }
+    originRepoCache.delete(oldestKey)
+  }
+}
+
 /**
  * Host-qualified repository identity for one remote: github.com remotes come
  * from the cached slug parser; any other GitHub-shaped host is auth-gated so a
@@ -56,8 +77,10 @@ export async function getGitHubApiRepositoryForRemote(
     return { ...ownerRepo, host: 'github.com' }
   }
   const cacheKey = originRepoCacheKey(repoPath, remoteName, connectionId, localGitOptions)
+  const now = Date.now()
+  pruneOriginRepoCache(now)
   const cached = originRepoCache.get(cacheKey)
-  if (cached && cached.expiresAt > Date.now()) {
+  if (cached && cached.expiresAt > now) {
     return cached.value
   }
   const inFlight = originRepoInFlight.get(cacheKey)
@@ -77,6 +100,7 @@ export async function getGitHubApiRepositoryForRemote(
             enterpriseOptions
           )
     originRepoCache.set(cacheKey, { value: slug, expiresAt: Date.now() + ORIGIN_REPO_CACHE_TTL_MS })
+    pruneOriginRepoCache(Date.now())
     return slug
   })()
   originRepoInFlight.set(cacheKey, probe)
@@ -241,11 +265,11 @@ export function githubRepositoryWebHost(repository: GitHubApiRepository): string
 /**
  * Positional `HOST/OWNER/REPO` argv value (e.g. `gh repo view <slug>`).
  * Positional slugs bypass the runner's `--repo` qualifier, so they must be
- * qualified here; github.com stays bare for compatibility with gh's default.
+ * qualified here whenever the host is known.
  */
 export function githubRepositorySlugArg(repository: GitHubApiRepository): string {
   const slug = `${repository.owner}/${repository.repo}`
-  return repository.host && !isDefaultGitHubHost(repository.host)
-    ? `${repository.host}/${slug}`
-    : slug
+  // Why: github.com must be explicit too; otherwise process-level GH_HOST can
+  // redirect positional `gh repo view OWNER/REPO` calls to an Enterprise host.
+  return repository.host ? `${repository.host}/${slug}` : slug
 }
diff --git a/src/main/github/github-enterprise-repository.ts b/src/main/github/github-enterprise-repository.ts
index 1986ce11afb..bd832a229e8 100644
--- a/src/main/github/github-enterprise-repository.ts
+++ b/src/main/github/github-enterprise-repository.ts
@@ -20,6 +20,7 @@ export type GitHubEnterpriseRepoSlug = GitHubOwnerRepo & { host: string }
 // mirrors the `glab auth status` signal GitLab self-hosted detection uses, so a
 // GHES remote is not left to fall through to Gitea (#8312).
 const HOST_AUTH_TTL_MS = 60_000
+const HOST_AUTH_CACHE_MAX_ENTRIES = 512
 
 type HostAuthCacheEntry = {
   authenticated: boolean
@@ -43,6 +44,26 @@ export function _resetGitHubHostAuthCache(): void {
   hostAuthInFlight.clear()
 }
 
+/** @internal - exposed for cache-bound tests only */
+export function _getGitHubHostAuthCacheSize(): number {
+  return hostAuthCache.size
+}
+
+function pruneHostAuthCache(now: number): void {
+  for (const [key, entry] of hostAuthCache) {
+    if (entry.expiresAt <= now) {
+      hostAuthCache.delete(key)
+    }
+  }
+  while (hostAuthCache.size > HOST_AUTH_CACHE_MAX_ENTRIES) {
+    const oldestKey = hostAuthCache.keys().next().value
+    if (oldestKey === undefined) {
+      return
+    }
+    hostAuthCache.delete(oldestKey)
+  }
+}
+
 // Only gh's own stdout/stderr — not the Error.message — counts as an
 // authoritative answer. A spawn failure (gh missing, ENOENT) carries just a
 // message and no command output, and must stay indeterminate rather than be
@@ -72,6 +93,7 @@ export async function isGitHubHostAuthenticated(
   const normalizedHost = host.toLowerCase()
   const cacheKey = `${runtimeCacheKey(connectionId, localGitOptions.wslDistro)}\0${normalizedHost}`
   const now = Date.now()
+  pruneHostAuthCache(now)
   const cached = hostAuthCache.get(cacheKey)
   if (cached && cached.expiresAt > now) {
     return cached.authenticated
@@ -107,6 +129,7 @@ export async function isGitHubHostAuthenticated(
       )
     }
     hostAuthCache.set(cacheKey, { authenticated, expiresAt: Date.now() + HOST_AUTH_TTL_MS })
+    pruneHostAuthCache(Date.now())
     return authenticated
   })()
   hostAuthInFlight.set(cacheKey, probe)
diff --git a/src/main/github/github-remote-identity-parsing.ts b/src/main/github/github-remote-identity-parsing.ts
index e7bd21242f1..e04683dd931 100644
--- a/src/main/github/github-remote-identity-parsing.ts
+++ b/src/main/github/github-remote-identity-parsing.ts
@@ -5,7 +5,9 @@ export type GitHubRemoteIdentity = GitHubOwnerRepo & { host: string }
 function normalizeGitHubRemoteHost(host: string): string {
   const normalizedHost = host.toLowerCase()
   // Why: GitHub documents ssh.github.com:443 as SSH-over-HTTPS for github.com repos.
-  return normalizedHost === 'ssh.github.com' ? 'github.com' : normalizedHost
+  return normalizedHost === 'ssh.github.com' || normalizedHost === 'ssh.github.com:443'
+    ? 'github.com'
+    : normalizedHost
 }
 
 function parseGitHubRemotePath(path: string): Pick<GitHubRemoteIdentity, 'owner' | 'repo'> | null {
@@ -34,7 +36,9 @@ export function parseGitHubRemoteIdentity(remoteUrl: string): GitHubRemoteIdenti
       return null
     }
     const path = parseGitHubRemotePath(url.pathname)
-    return path ? { host: normalizeGitHubRemoteHost(url.hostname), ...path } : null
+    // Why: GHES may be served on a non-default port. `hostname` silently drops
+    // it, sending authenticated API calls to a different endpoint on port 443.
+    return path ? { host: normalizeGitHubRemoteHost(url.host), ...path } : null
   } catch {
     return null
   }
diff --git a/src/preload/api-types.ts b/src/preload/api-types.ts
index 5479cbd7805..de4901970cf 100644
--- a/src/preload/api-types.ts
+++ b/src/preload/api-types.ts
@@ -1520,6 +1520,7 @@ export type PreloadApi = {
       repoId?: string
       owner: string
       repo: string
+      host?: string
       number: number
       type: 'issue' | 'pr'
     }) => Promise<Omit<GitHubWorkItem, 'repoId'> | null>
@@ -1715,8 +1716,8 @@ export type PreloadApi = {
      * `force: true` to bust after a known-expensive op.
      */
     rateLimit: (args?: { force?: boolean }) => Promise<GetRateLimitResult>
-  /** Explains scope_missing ProjectV2 failures — notably a shell `GITHUB_TOKEN` shadowing the keyring credential, where `gh auth refresh` is a no-op. */
-  diagnoseAuth: (args?: { host?: string }) => Promise<GhAuthDiagnostic>
+    /** Explains scope_missing ProjectV2 failures — notably a shell `GITHUB_TOKEN` shadowing the keyring credential, where `gh auth refresh` is a no-op. */
+    diagnoseAuth: (args?: { host?: string }) => Promise<GhAuthDiagnostic>
     // ── ProjectV2 (GitHub Projects) ─────────────────────────────────
     listAccessibleProjects: (
       args?: ListAccessibleProjectsArgs
diff --git a/src/renderer/src/components/new-workspace/SmartWorkspaceNameField.tsx b/src/renderer/src/components/new-workspace/SmartWorkspaceNameField.tsx
index f2749139eac..963c32143a2 100644
--- a/src/renderer/src/components/new-workspace/SmartWorkspaceNameField.tsx
+++ b/src/renderer/src/components/new-workspace/SmartWorkspaceNameField.tsx
@@ -81,6 +81,7 @@ import {
   type TaskSourceContext
 } from '../../../../shared/task-source-context'
 import { parseExecutionHostId, type ExecutionHostId } from '../../../../shared/execution-host'
+import { githubRepoIdentityKey } from '../../../../shared/github-repository-identity-key'
 
 type RepoOption = ReturnType<typeof useAppStore.getState>['repos'][number]
 const EMPTY_REPO_SEARCH_REPOS: readonly RepoOption[] = []
@@ -577,6 +578,7 @@ export default function SmartWorkspaceNameField({
             sourceContext: target.githubSourceContext,
             owner: directLink.slug.owner,
             repo: directLink.slug.repo,
+            ...(directLink.slug.host ? { host: directLink.slug.host } : {}),
             number: directLink.number,
             type: directLink.type
           })
@@ -599,6 +601,7 @@ export default function SmartWorkspaceNameField({
               kind: 'link',
               owner: directLink.slug.owner,
               repo: directLink.slug.repo,
+              ...(directLink.slug.host ? { host: directLink.slug.host } : {}),
               number: directLink.number,
               type: directLink.type
             },
@@ -647,6 +650,7 @@ export default function SmartWorkspaceNameField({
               kind: 'link' as const,
               owner: directLink.slug.owner,
               repo: directLink.slug.repo,
+              ...(directLink.slug.host ? { host: directLink.slug.host } : {}),
               number: directLink.number,
               type: directLink.type
             }
@@ -1128,6 +1132,7 @@ export default function SmartWorkspaceNameField({
           sourceContext,
           owner: crossRepoPrompt.link.slug.owner,
           repo: crossRepoPrompt.link.slug.repo,
+          ...(crossRepoPrompt.link.slug.host ? { host: crossRepoPrompt.link.slug.host } : {}),
           number: crossRepoPrompt.link.number,
           type: crossRepoPrompt.link.type
         })
@@ -1748,10 +1753,7 @@ function RowLabel({ row }: { row: RowEntry }): React.JSX.Element {
 }
 
 function sameSlug(left: RepoSlug, right: RepoSlug): boolean {
-  return (
-    left.owner.toLowerCase() === right.owner.toLowerCase() &&
-    left.repo.toLowerCase() === right.repo.toLowerCase()
-  )
+  return githubRepoIdentityKey(left) === githubRepoIdentityKey(right)
 }
 
 async function getRepoSlugCached(
diff --git a/src/renderer/src/hooks/useComposerState.ts b/src/renderer/src/hooks/useComposerState.ts
index accc351ca50..6e617d6d644 100644
--- a/src/renderer/src/hooks/useComposerState.ts
+++ b/src/renderer/src/hooks/useComposerState.ts
@@ -1890,6 +1890,9 @@ export function useComposerState(options: UseComposerStateOptions): UseComposerS
             sourceContext: selectedRepoGitHubSourceContext,
             owner: normalizedLinkQuery.directLink.slug.owner,
             repo: normalizedLinkQuery.directLink.slug.repo,
+            ...(normalizedLinkQuery.directLink.slug.host
+              ? { host: normalizedLinkQuery.directLink.slug.host }
+              : {}),
             number: normalizedLinkQuery.directLink.number,
             type: normalizedLinkQuery.directLink.type
           })
diff --git a/src/renderer/src/lib/github-work-item-source-lookup.ts b/src/renderer/src/lib/github-work-item-source-lookup.ts
index e12de08b3b0..046c4af0790 100644
--- a/src/renderer/src/lib/github-work-item-source-lookup.ts
+++ b/src/renderer/src/lib/github-work-item-source-lookup.ts
@@ -18,6 +18,7 @@ type GitHubWorkItemLookupArgs = {
 type GitHubWorkItemByOwnerRepoLookupArgs = GitHubWorkItemLookupArgs & {
   owner: string
   repo: string
+  host?: string
   type: 'issue' | 'pr'
 }
 
@@ -71,6 +72,7 @@ export async function lookupGitHubWorkItemByOwnerRepoForSource(
             repo: runtimeRepoId(args),
             owner: args.owner,
             ownerRepo: args.repo,
+            ...(args.host ? { host: args.host } : {}),
             number: args.number,
             type: args.type
           },
@@ -81,6 +83,7 @@ export async function lookupGitHubWorkItemByOwnerRepoForSource(
           repoId: args.repoId,
           owner: args.owner,
           repo: args.repo,
+          ...(args.host ? { host: args.host } : {}),
           number: args.number,
           type: args.type
         })
diff --git a/src/renderer/src/lib/smart-github-submit.ts b/src/renderer/src/lib/smart-github-submit.ts
index 1b4e818f26a..748c84161fe 100644
--- a/src/renderer/src/lib/smart-github-submit.ts
+++ b/src/renderer/src/lib/smart-github-submit.ts
@@ -5,12 +5,14 @@ import { getLinkedWorkItemWorkspaceName } from '../../../shared/workspace-name'
 import type { LinkedWorkItemSummary } from './new-workspace'
 import { parseGitHubIssueOrPRLink } from './github-links'
 import { resolveGitHubWorkItemIdentity } from '@/lib/github-work-item-identity'
+import { githubRepoIdentityKey } from '../../../shared/github-repository-identity-key'
 
 export type SmartGitHubSubmitIntent =
   | {
       kind: 'link'
       owner: string
       repo: string
+      host?: string
       number: number
       type: 'issue' | 'pr'
     }
@@ -48,6 +50,7 @@ export type SmartGitHubSubmitLookup = {
     sourceContext?: TaskSourceContext | null
     owner: string
     repo: string
+    host?: string
     number: number
     type: 'issue' | 'pr'
   }) => Promise<GitHubWorkItem | null>
@@ -92,6 +95,7 @@ export function getSmartGitHubSubmitIntent(input: string): SmartGitHubSubmitInte
       kind: 'link',
       owner: link.slug.owner,
       repo: link.slug.repo,
+      ...(link.slug.host ? { host: link.slug.host } : {}),
       number: link.number,
       type: link.type
     }
@@ -132,9 +136,7 @@ function getSmartGitHubSubmitLookupCacheKey({
   if (intent.kind === 'hash-number') {
     return `${repoScope}:hash:${intent.number}`
   }
-  return `${repoScope}:link:${intent.owner.toLowerCase()}/${intent.repo.toLowerCase()}:${
-    intent.type
-  }:${intent.number}`
+  return `${repoScope}:link:${githubRepoIdentityKey(intent)}:${intent.type}:${intent.number}`
 }
 
 export function lookupSmartGitHubSubmitItem({
@@ -161,6 +163,7 @@ export function lookupSmartGitHubSubmitItem({
           sourceContext,
           owner: intent.owner,
           repo: intent.repo,
+          ...(intent.host ? { host: intent.host } : {}),
           number: intent.number,
           type: intent.type
         })
diff --git a/src/shared/github-links.ts b/src/shared/github-links.ts
index 8f122ba4ac8..ee82d811db6 100644
--- a/src/shared/github-links.ts
+++ b/src/shared/github-links.ts
@@ -101,7 +101,9 @@ export function parseGitHubIssueOrPRLink(input: string): GitHubIssueOrPRLink | n
   return {
     // Why: the URL proves the host — GHES links must keep their server identity
     // instead of being treated as github.com slugs.
-    slug: { owner: match[1], repo: match[2], host: url.hostname },
+    // Why: GHES installations on non-default ports require the full URL host;
+    // `hostname` would silently redirect later API calls to port 443.
+    slug: { owner: match[1], repo: match[2], host: url.host },
     type: match[3].toLowerCase() === 'pull' ? 'pr' : 'issue',
     number
   }
diff --git a/src/shared/terminal-github-pr-link-detector.test.ts b/src/shared/terminal-github-pr-link-detector.test.ts
index 23a00fe493d..c2a6cc3c5bf 100644
--- a/src/shared/terminal-github-pr-link-detector.test.ts
+++ b/src/shared/terminal-github-pr-link-detector.test.ts
@@ -156,8 +156,8 @@ describe('createTerminalGitHubPRLinkDetector', () => {
     expect(observe('Created https://github.internal:8443/MyOrg/my_repo/pull/397\r\n')).toEqual([
       {
         url: 'https://github.internal:8443/MyOrg/my_repo/pull/397',
-        // Ports are dropped to match parseGitHubRemoteIdentity's hostname identity.
-        slug: { owner: 'MyOrg', repo: 'my_repo', host: 'github.internal' },
+        // Why: GHES on a non-default port needs the port in its host identity.
+        slug: { owner: 'MyOrg', repo: 'my_repo', host: 'github.internal:8443' },
         number: 397
       }
     ])