[macOS][Chat] Cannot send follow-up messages after the initial response

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

26.715.21425

What subscription do you have?

ChatGPT Pro

What platform is your computer?

Darwin 27.0.0 arm64 arm

What issue are you seeing?

In the current unified ChatGPT desktop app, I cannot continue a conversation in Chat mode after the first assistant response. When I try to ask a follow-up question in the same conversation, I cannot send another message and the conversation effectively ends after one exchange.

This is not about the earlier compact or side-panel Chat interface. Chat is now fully integrated into the main app, but normal multi-turn conversation is not available in this flow.

What steps can reproduce the bug?

1. Open the current ChatGPT desktop app on macOS.
2. Select Chat.
3. Open a conversation.
4. Send a message and wait for the assistant response to finish.
5. Try to send a follow-up message in the same conversation.
6. Observe that the conversation cannot be continued with the follow-up message.

What is the expected behavior?

The message composer should remain available after every assistant response, and I should be able to send follow-up messages in the same conversation. The existing conversation context should be preserved so that Chat supports a normal multi-turn conversation.

Additional information

This report concerns the current fully integrated Chat interface in version 26.715.21425 (build 5488).

It is different from #32570, which describes the earlier compact/side-panel Chat UI and the missing “Ask ChatGPT” action for selected text.

Session ID: not available.