diff --git a/src/main/providers/ssh-pty-provider.test.ts b/src/main/providers/ssh-pty-provider.test.ts
index 40301906f52..64b133e08ee 100644
--- a/src/main/providers/ssh-pty-provider.test.ts
+++ b/src/main/providers/ssh-pty-provider.test.ts
@@ -584,7 +584,8 @@ describe('SshPtyProvider', () => {
           id: 'pty-old',
           cols: 80,
           rows: 24,
-          suppressReplayNotification: true
+          suppressReplayNotification: true,
+          requireReplay: true
         },
         sourceActivationRequestOptions
       )
@@ -630,7 +631,8 @@ describe('SshPtyProvider', () => {
         id: 'pty-old',
         cols: 80,
         rows: 24,
-        suppressReplayNotification: true
+        suppressReplayNotification: true,
+        requireReplay: true
       })
       expect(result).toEqual({
         id: 'ssh:conn-1@@pty-old',
@@ -655,6 +657,7 @@ describe('SshPtyProvider', () => {
         cols: 80,
         rows: 24,
         suppressReplayNotification: true,
+        requireReplay: true,
         expectedPaneKey: 'tab-a:leaf-a',
         expectedTabId: 'tab-a'
       })
@@ -674,7 +677,8 @@ describe('SshPtyProvider', () => {
           id: 'pty-old',
           cols: 80,
           rows: 24,
-          suppressReplayNotification: true
+          suppressReplayNotification: true,
+          requireReplay: true
         },
         sourceActivationRequestOptions
       )
diff --git a/src/main/providers/ssh-pty-session-reattach.ts b/src/main/providers/ssh-pty-session-reattach.ts
index 34974940caf..a3756681f9d 100644
--- a/src/main/providers/ssh-pty-session-reattach.ts
+++ b/src/main/providers/ssh-pty-session-reattach.ts
@@ -196,6 +196,12 @@ export async function reattachSshPtySession(args: {
         cols: args.options.cols,
         rows: args.options.rows,
         suppressReplayNotification: true,
+        // A reattach always paints into a NEW terminal: a reconnect bumps tab.generation, which is
+        // the pane's React key, so TerminalPane remounts and the old xterm is disposed with its
+        // buffer. Without this the relay sees a delivery still open under our unchanged client id,
+        // answers "you already have this", and the pane stays blank until new output arrives.
+        // Optional on the wire, so an older relay simply ignores it and behaves as it does today.
+        requireReplay: true,
         ...(expectedPaneKey ? { expectedPaneKey } : {}),
         ...(expectedTabId ? { expectedTabId } : {})
       },
@@ -203,7 +209,8 @@ export async function reattachSshPtySession(args: {
       rememberPtyIncarnation: args.rememberPtyIncarnation
     })
     console.warn(
-      `[ssh-pty] pty.attach succeeded for ${args.sessionId}, replay=${!!attachResult.replay}`
+      `[ssh-pty] pty.attach succeeded for ${args.sessionId}, replay=${!!attachResult.replay}` +
+        `, replayLen=${attachResult.replay?.length ?? 0}`
     )
     return {
       id: toAppSshPtyId(args.connectionId, relaySessionId),
diff --git a/src/relay/pty-handler-source-publication.test.ts b/src/relay/pty-handler-source-publication.test.ts
index 04e45d2b384..f0041a57ce5 100644
--- a/src/relay/pty-handler-source-publication.test.ts
+++ b/src/relay/pty-handler-source-publication.test.ts
@@ -769,4 +769,47 @@ describe('PtyHandler negotiated source publication', () => {
     expect(publication.getDebugSnapshot()).toMatchObject({ sendCommitted: 1 })
     expect(pausePty).not.toHaveBeenCalled()
   })
+
+  // The reported defect, in the shape measured against the live relay: the client attaches twice
+  // for the same PTY. The first registers a source delivery under the primary client's id; the
+  // second finds `current.clientId === context.clientId`, answers 'existing', and returns NO
+  // replay. Live, every pane on reconnect logged path=existing-delivery and painted nothing.
+  //
+  // A reattach always lands in a NEW terminal — a reconnect bumps tab.generation, which is the
+  // pane's React key, so TerminalPane remounts and the old xterm is disposed with its buffer.
+  describe('a second attach for the same client', () => {
+    async function attach(id: number, params: Record<string, unknown>) {
+      writes = []
+      dispatcher.feed(requestFrame(id, 'pty.attach', { id: 'pty-1', ...params }))
+      await vi.advanceTimersByTimeAsync(0)
+      return writes.map((buffer) => responseResult(buffer, id)).find(Boolean)
+    }
+
+    beforeEach(async () => {
+      await spawn({})
+      dataCallback!('scrollback-that-must-survive')
+      await vi.advanceTimersByTimeAsync(10)
+      await attach(10, { suppressReplayNotification: true })
+    })
+
+    it('replays the scrollback when the client says it needs it', async () => {
+      const second = await attach(11, {
+        suppressReplayNotification: true,
+        requireReplay: true
+      })
+
+      expect(second, 'second attach returned no response').toBeTruthy()
+      expect(second!.replay).toContain('scrollback-that-must-survive')
+    })
+
+    // The early return is right for a duplicate attach from a client that IS still receiving the
+    // stream; only a client that has thrown its terminal away should ask. Pinned so the fix stays
+    // opt-in and cannot start double-rendering for callers that never asked.
+    it('still sends nothing when the client does not ask', async () => {
+      const second = await attach(12, { suppressReplayNotification: true })
+
+      expect(second, 'second attach returned no response').toBeTruthy()
+      expect(second!.replay).toBeUndefined()
+    })
+  })
 })
diff --git a/src/relay/pty-handler.ts b/src/relay/pty-handler.ts
index c077378ebda..31f3e81fea9 100644
--- a/src/relay/pty-handler.ts
+++ b/src/relay/pty-handler.ts
@@ -1732,7 +1732,23 @@ export class PtyHandler {
         ...(sourceActivation ? { sourceActivation } : {})
       }
     }
-    if (activation === 'existing' && this.sourcePublication?.accepts(id)) {
+    // `existing` means a delivery is already open for this client, so it is already receiving live
+    // output and does not need its screen re-sent. That is true for a duplicate attach — and false
+    // for the case this skipped: an SSH reconnect. The client keeps its id there (the dispatcher
+    // refuses to detach the primary, and setWrite revives that same id), so the delivery outlives
+    // the dead transport, while the renderer has thrown its terminal away — a reconnect bumps
+    // tab.generation, which is the React key, so the pane remounts with a brand-new empty xterm and
+    // nothing captures the old buffer. Answering "you already have it" leaves the pane blank
+    // forever, until new output happens to arrive.
+    //
+    // So the client says which it is. Falling through rather than returning the replay inline is
+    // deliberate: the path below already drops the pending batched bytes that are also in the
+    // buffer, which is what stops the live delivery double-rendering them.
+    if (
+      activation === 'existing' &&
+      this.sourcePublication?.accepts(id) &&
+      params.requireReplay !== true
+    ) {
       return {
         incarnationId: managed.incarnationId,
         ...(sourceActivation ? { sourceActivation } : {})