[Windows][Remote Control] Remote connection stopped working after update; re-registration and network changes do not recover it

What version of the Codex App are you using (From “About Codex” dialog)?

Latest Windows Codex App update available on 2026-08-21. Exact build number was not captured before filing.

What subscription do you have?

ChatGPT plan with Codex access.

What platform is your computer?

Windows desktop. Remote client is the ChatGPT Android app.

What issue are you seeing?

Codex Remote Control worked normally through 2026-08-20, but stopped connecting on the morning of 2026-08-21.

The desktop Codex app is running. I updated it to the latest available version and restarted it. I also removed/re-registered the device, but Remote Control still does not recover.

On the mobile side, there was no newer ChatGPT app update available, and restarting the mobile app did not help.

I also tested the mobile client on both Wi-Fi and cellular data. The failure is unchanged on both networks, so this does not appear to be a simple local-network issue.

What steps can reproduce the bug?

1. Have a Windows Codex desktop already paired with ChatGPT mobile Remote Control and working normally.
2. Update/restart the Windows Codex app.
3. Open the Remote Control flow from the ChatGPT Android app.
4. Observe that the previously working remote connection no longer works.
5. Remove/re-register the desktop device.
6. Restart both the desktop Codex app and the mobile ChatGPT app.
7. Try again on Wi-Fi.
8. Try again on cellular/mobile data.
9. Observe that Remote Control still does not recover.

What is the expected behavior?

A running and successfully registered Windows Codex desktop should become reachable again from the ChatGPT mobile app. Re-registering the device should establish a fresh working remote session.

If connection cannot be established, the UI should expose a diagnostic state/error (host heartbeat, auth/session mismatch, WebSocket/backend status, last-seen timestamp, or a request/correlation ID) so the failure can be distinguished from a stale registration or server-side issue.

Additional information

• This setup worked normally until the previous day.
• Desktop Codex was confirmed running.
• Desktop Codex was updated and restarted.
• Device registration was recreated.
• ChatGPT Android app had no update pending and was restarted.
• Both Wi-Fi and cellular networks were tested with the same result.
• Because registration and two independent mobile networks were tested, this appears more consistent with a Remote Control/session/backend regression than a simple pairing or network configuration problem.

Potentially related reports:

• #31973 — Windows Remote Control stuck in Reconnecting
• #22715 — desktop authorized but mobile waits for desktop

I am filing this separately because in this case re-registering the device, restarting both clients, and changing the mobile network all failed to recover a setup that had been working the day before.