[macOS 26.715.12143] Enabling “Control this Mac” briefly shows mobile device, then fails with remote-state / single-instance errors

Start by reproducing the failure from Settings → Connections → Control this Mac in ChatGPT Desktop for macOS 26.715.12143, then trace the “Failed to update remote status” and apparent single-instance errors. Done means Allow connections remains enabled, the Mac registers as a remote-control host, and the discovered mobile device remains available without retries.

What version of the Codex/ChatGPT App are you using?

ChatGPT Desktop for macOS 26.715.12143.

What subscription do you have?

ChatGPT Prolite.

What platform is your computer?

macOS. Exact macOS version and CPU architecture are not available at the time of reporting.

What issue are you seeing?

In Settings → Connections → Control this Mac, enabling Allow connections does not persist.

On the first attempt, the user's mobile device appears briefly in the remote-control UI, then the app reports an error equivalent to:

Failed to update remote status.

On the second attempt to enable the toggle, the app reports:

Unable to enable remote control. Please make sure only one ChatGPT instance is running.

The user reports that only the current ChatGPT macOS app is intentionally in use. They also fully quit/restarted ChatGPT and checked for duplicate ChatGPT/Codex/ChatGPT Classic instances before retrying.

This looks like either:

• a stale local single-instance/remote-control lock,
• duplicate host enrollment being detected incorrectly, or
• a race while updating the remote-control host state after the mobile device is discovered.

Steps to reproduce

1. Launch ChatGPT Desktop 26.715.12143 on macOS.
2. Open Settings → Connections → Control this Mac.
3. Turn on Allow connections.
4. Observe that a signed-in mobile device appears briefly.
5. Observe the error: Failed to update remote status.
6. Turn on Allow connections again.
7. Observe the error asking the user to ensure only one ChatGPT instance is running.

Expected behavior

The toggle should remain enabled, the Mac should register as a remote-control host, and the mobile device should remain available without requiring multiple retries.

Actual behavior

The remote-control state fails to update, and subsequent attempts are blocked by an apparent false-positive single-instance check.

Additional information

• Keep this Mac awake is enabled.
• The failure occurs in the new unified ChatGPT macOS app UI under Connections.
• A screenshot is available showing the affected Control this Mac → Allow connections toggle, but it could not be attached through the connector used to submit this report.
• No exact duplicate was found when searching the existing openai/codex issues for the single-instance error text.