diff --git a/src/main/ipc/runtime.test.ts b/src/main/ipc/runtime.test.ts
index f951091c986..58e42ad5262 100644
--- a/src/main/ipc/runtime.test.ts
+++ b/src/main/ipc/runtime.test.ts
@@ -99,4 +99,44 @@ describe('registerRuntimeHandlers', () => {
       _meta: { runtimeId: 'runtime-1' }
     })
   })
+
+  it('deduplicates retries while a terminal fit restore is still pending', async () => {
+    const finishRestoreByPtyId = new Map<string, (restored: boolean) => void>()
+    const reclaimTerminalForDesktop = vi.fn(
+      (ptyId: string) =>
+        new Promise<boolean>((resolve) => {
+          finishRestoreByPtyId.set(ptyId, resolve)
+        })
+    )
+    const runtime = {
+      syncWindowGraph: vi.fn(),
+      getStatus: vi.fn(),
+      reclaimTerminalForDesktop
+    }
+    registerRuntimeHandlers(runtime as never)
+    const restoreRegistration = handleMock.mock.calls.find(
+      ([channel]) => channel === 'runtime:restoreTerminalFit'
+    )
+    expect(restoreRegistration).toBeTruthy()
+    const handler = restoreRegistration![1]
+
+    const first = handler({ sender: {} }, { ptyId: 'pty-1' })
+    const retry = handler({ sender: {} }, { ptyId: 'pty-1' })
+    const otherTerminal = handler({ sender: {} }, { ptyId: 'pty-2' })
+
+    expect(reclaimTerminalForDesktop).toHaveBeenCalledTimes(2)
+    expect(reclaimTerminalForDesktop).toHaveBeenNthCalledWith(1, 'pty-1')
+    expect(reclaimTerminalForDesktop).toHaveBeenNthCalledWith(2, 'pty-2')
+    finishRestoreByPtyId.get('pty-1')?.(true)
+    finishRestoreByPtyId.get('pty-2')?.(true)
+    await expect(otherTerminal).resolves.toEqual({ restored: true })
+    await expect(first).resolves.toEqual({ restored: true })
+    await expect(retry).resolves.toEqual({ restored: true })
+    expect(reclaimTerminalForDesktop).toHaveBeenCalledTimes(2)
+
+    const afterSettlement = handler({ sender: {} }, { ptyId: 'pty-1' })
+    expect(reclaimTerminalForDesktop).toHaveBeenCalledTimes(3)
+    finishRestoreByPtyId.get('pty-1')?.(false)
+    await expect(afterSettlement).resolves.toEqual({ restored: false })
+  })
 })
diff --git a/src/main/ipc/runtime.ts b/src/main/ipc/runtime.ts
index 3b9a8719afc..7991035ee8c 100644
--- a/src/main/ipc/runtime.ts
+++ b/src/main/ipc/runtime.ts
@@ -11,6 +11,7 @@ import type { RuntimeRpcResponse } from '../../shared/runtime-rpc-envelope'
 import { RpcDispatcher } from '../runtime/rpc/dispatcher'
 
 export function registerRuntimeHandlers(runtime: OrcaRuntimeService): void {
+  const pendingTerminalFitRestores = new Map<string, Promise<boolean>>()
   ipcMain.removeHandler('runtime:syncWindowGraph')
   ipcMain.removeHandler('runtime:getStatus')
   ipcMain.removeHandler('runtime:call')
@@ -101,11 +102,25 @@ export function registerRuntimeHandlers(runtime: OrcaRuntimeService): void {
     // Electron try to structured-clone a Promise — "An object could not
     // be cloned" error — and the renderer's restoreTerminalFit() rejected
     // with no useful info.
+    // Why: renderer timeouts must not turn retries into duplicate waiters behind one stuck reclaim.
+    let pending = pendingTerminalFitRestores.get(args.ptyId)
+    if (!pending) {
+      try {
+        pending = runtime.reclaimTerminalForDesktop(args.ptyId)
+        pendingTerminalFitRestores.set(args.ptyId, pending)
+      } catch {
+        return { restored: false }
+      }
+    }
     try {
-      const reclaimed = await runtime.reclaimTerminalForDesktop(args.ptyId)
+      const reclaimed = await pending
       return { restored: reclaimed }
     } catch {
       return { restored: false }
+    } finally {
+      if (pendingTerminalFitRestores.get(args.ptyId) === pending) {
+        pendingTerminalFitRestores.delete(args.ptyId)
+      }
     }
   })
 
diff --git a/src/main/runtime/rpc/relay-transport.test.ts b/src/main/runtime/rpc/relay-transport.test.ts
index e1f2d7fa76f..6a88fb8df49 100644
--- a/src/main/runtime/rpc/relay-transport.test.ts
+++ b/src/main/runtime/rpc/relay-transport.test.ts
@@ -189,6 +189,7 @@ describe('CloudRelayTransport', () => {
       emit('close')
       expect(listeners.get('error')).toHaveLength(0)
       expect(listeners.get('close')).toHaveLength(0)
+      expect(vi.getTimerCount()).toBe(0)
       expect(() => transport.setGeneration(2)).not.toThrow()
     } finally {
       vi.useRealTimers()
@@ -241,6 +242,74 @@ describe('CloudRelayTransport', () => {
     }
   })
 
+  it('releases an expired attach even when terminate never emits close', async () => {
+    vi.useFakeTimers()
+    try {
+      const listeners = new Map<string, ((...args: unknown[]) => void)[]>()
+      const addListener = (event: string, fn: (...args: unknown[]) => void): void => {
+        listeners.set(event, [...(listeners.get(event) ?? []), fn])
+      }
+      const removeListener = (event: string, fn: (...args: unknown[]) => void): void => {
+        listeners.set(
+          event,
+          (listeners.get(event) ?? []).filter((listener) => listener !== fn)
+        )
+      }
+      const emit = (event: string, ...args: unknown[]): void => {
+        const eventListeners = listeners.get(event) ?? []
+        if (event === 'error' && eventListeners.length === 0) {
+          throw args[0]
+        }
+        for (const fn of eventListeners) {
+          fn(...args)
+        }
+      }
+      const fakeSocket = {
+        readyState: 0,
+        OPEN: 1,
+        CLOSED: 3,
+        on: addListener,
+        once: addListener,
+        off: removeListener,
+        send: vi.fn(),
+        terminate: vi.fn()
+      }
+      const onConnectionClosed = vi.fn()
+      const transport = new CloudRelayTransport({
+        cellUrl: 'http://127.0.0.1:9',
+        relayHostId: 'AbCdEf0123_-xyZ9',
+        generation: 1,
+        createSocket: () => fakeSocket as unknown as WebSocketClient,
+        onConnectionClosed
+      })
+      const opening = transport.openConnection({
+        connId: 'conn-attach-timeout',
+        connTicket: 'ticket-1',
+        kind: 'resume',
+        relayDeviceId: 'device-1',
+        attachDeadlineMs: 1_000
+      })
+      const rejectedOpening = expect(opening).rejects.toThrow('relay_host_data_attach_timeout')
+
+      await vi.advanceTimersByTimeAsync(1_000)
+
+      await rejectedOpening
+      expect(fakeSocket.terminate).toHaveBeenCalledOnce()
+      expect(onConnectionClosed).toHaveBeenCalledWith('conn-attach-timeout')
+      expect(() => transport.metadataFor(fakeSocket as unknown as WebSocketClient)).toThrow(
+        'unknown_relay_socket'
+      )
+      expect(() => transport.setGeneration(2)).not.toThrow()
+      expect(() => emit('message', 'late-after-attach-timeout', false)).not.toThrow()
+      expect(() => emit('error', new Error('late attach socket failure'))).not.toThrow()
+      emit('close')
+      expect(listeners.get('error')).toHaveLength(0)
+      expect(listeners.get('close')).toHaveLength(0)
+    } finally {
+      vi.useRealTimers()
+    }
+  })
+
   it('rejects non-origin cell URLs before opening a socket', () => {
     expect(
       () =>
diff --git a/src/main/runtime/rpc/relay-transport.ts b/src/main/runtime/rpc/relay-transport.ts
index fdb7e50a20f..2442ae1aef6 100644
--- a/src/main/runtime/rpc/relay-transport.ts
+++ b/src/main/runtime/rpc/relay-transport.ts
@@ -150,6 +150,9 @@ export class CloudRelayTransport implements RpcTransport, MobileSocketTransport
       let finalized = false
       const deadline = setTimeout(() => {
         socket.terminate()
+        // Why: attach expiry makes the socket unusable; release it even if terminate never emits close.
+        finalize()
+        this.quarantineDetachedSocket(socket)
         if (!opened) {
           reject(new Error('relay_host_data_attach_timeout'))
         }