diff --git a/src/main/daemon/degraded-daemon-pty-provider.ts b/src/main/daemon/degraded-daemon-pty-provider.ts
index 545f66ca892..ec85118e5b7 100644
--- a/src/main/daemon/degraded-daemon-pty-provider.ts
+++ b/src/main/daemon/degraded-daemon-pty-provider.ts
@@ -14,6 +14,7 @@ import type {
 import {
   adoptOwningProvider,
   attachDaemonOwnedSession,
+  ownerForDaemonOwnedOperation,
   findDaemonAdapter,
   listProviderSessionIds
 } from './degraded-daemon-session-routing'
@@ -89,6 +90,11 @@ export class DegradedDaemonPtyProvider implements IPtyProvider {
   attach = (id: string): ReturnType<IPtyProvider['attach']> =>
     attachDaemonOwnedSession(this.providerFor(id), this.fallback, id)
 
+  /** Routing for anything that changes or feeds a session; see ownerForDaemonOwnedOperation. */
+  private ownerFor(id: string): IPtyProvider {
+    return ownerForDaemonOwnedOperation(this.providerFor(id), this.fallback, id)
+  }
+
   hasPty(id: string): boolean {
     const mapped = this.sessionProviders.get(id)
     return mapped ? (mapped.hasPty?.(id) ?? true) : this.findProviderForExistingSession(id) !== null
@@ -109,11 +115,11 @@ export class DegradedDaemonPtyProvider implements IPtyProvider {
     )?.providesAgentSessionOwnerListings?.(ptyId) === true
 
   write(id: string, data: string): void {
-    this.providerFor(id).write(id, data)
+    this.ownerFor(id).write(id, data)
   }
 
   resize(id: string, cols: number, rows: number): void {
-    this.providerFor(id).resize(id, cols, rows)
+    this.ownerFor(id).resize(id, cols, rows)
   }
 
   pauseProducer(id: string): void {
@@ -132,14 +138,14 @@ export class DegradedDaemonPtyProvider implements IPtyProvider {
     id: string,
     opts: { immediate?: boolean; keepHistory?: boolean; deadlineMs?: number }
   ): Promise<void> {
-    await this.providerFor(id).shutdown(id, opts)
+    await this.ownerFor(id).shutdown(id, opts)
     if (!opts.keepHistory) {
       this.sessionProviders.delete(id)
     }
   }
 
   async sendSignal(id: string, signal: string): Promise<void> {
-    await this.providerFor(id).sendSignal(id, signal)
+    await this.ownerFor(id).sendSignal(id, signal)
   }
 
   async getCwd(id: string): Promise<string> {
diff --git a/src/main/daemon/degraded-daemon-session-routing.ts b/src/main/daemon/degraded-daemon-session-routing.ts
index 7fb5a9a00c8..48aa3870baf 100644
--- a/src/main/daemon/degraded-daemon-session-routing.ts
+++ b/src/main/daemon/degraded-daemon-session-routing.ts
@@ -1,6 +1,6 @@
 import type { IPtyProvider } from '../providers/types'
 import type { DaemonPtyAdapter } from './daemon-pty-adapter'
-import { SessionNotFoundError } from './daemon-errors'
+import { SessionNotFoundError, TerminalSessionOwnerUnverifiedError } from './daemon-errors'
 
 export function listProviderSessionIds(
   sessionProviders: ReadonlyMap<string, IPtyProvider>,
@@ -26,6 +26,29 @@ export async function attachDaemonOwnedSession(
   return await owner.attach(sessionId)
 }
 
+/**
+ * Session operations that must never be answered by the in-process fallback on another
+ * provider's behalf. An unknown id resolves to the fallback, whose shutdown returns
+ * silently and whose write/resize are no-ops — so a daemon-owned session reads as closed
+ * while its agent keeps running, and typing into it disappears. Route there only when the
+ * fallback genuinely owns the pty; otherwise say the session cannot be reached.
+ *
+ * Why not SessionNotFoundError: pty:kill treats "Session not found" as proof the pty is
+ * already gone and synthesizes an exit, which is the same lie by another route. This one
+ * means "still there, we just cannot reach its host", so the kill is reported as failed and
+ * ownership is kept for a retry.
+ */
+export function ownerForDaemonOwnedOperation(
+  owner: IPtyProvider,
+  fallback: IPtyProvider,
+  sessionId: string
+): IPtyProvider {
+  if (owner === fallback && fallback.hasPty?.(sessionId) !== true) {
+    throw new TerminalSessionOwnerUnverifiedError(sessionId)
+  }
+  return owner
+}
+
 /** Probes providers for an id absent from the routing map and adopts the
  *  first proven owner into the map. */
 export function adoptOwningProvider(