Desktop task becomes unsendable and cannot be stopped until app restart

Summary

A Codex task became stuck in a client state where I could not send new messages and could not stop the apparent thinking state. The same task was unusable from both Work and Codex. Quitting and restarting the application restored normal behavior.

Affected task

019fc246-0b10-75e2-acfe-d666c96cd246

Observed behavior

• New messages could not be sent to the task.
• The apparent thinking state could not be stopped.
• The agent was actually idle, so the client state did not match backend activity.
• The problem affected the same task in both Work and Codex.
• There was no effective recovery action within the task UI.

Expected behavior

• Sending a message should work whenever the task is idle.
• The UI should not show an active thinking/stop state when no agent work is running.
• If task state becomes stale, the client should reconcile it automatically or provide an effective retry/reconnect action without requiring a full application restart.

Workaround

Quit the application completely and restart it. Messaging worked again after restart.

Environment

• macOS: 26.5.2 (build 25F84)
• ChatGPT desktop: 26.803.81509 (build 6415)
• Date observed: 2026-08-13, Pacific Time

Possible area to investigate

Inference: client/task-state synchronization or stale session metadata, because the agent was idle while the client would not accept messages or clear the apparent thinking state.