Voice input button disappears in existing chats but appears in new chats

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

26.72.1.41059

What subscription do you have?

ChatGPT Pro

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64

What issue are you seeing?

In the Codex desktop app, the voice input button is available when I open a new chat. However, during an existing conversation, the voice button sometimes disappears or becomes unavailable.

Starting a fresh chat makes the voice button appear and work again.

Feedback ID: 019f805c-8d6f-7061-9b39-6a1f80fcbed2

What steps can reproduce the bug?

1. Open the ChatGPT/Codex desktop app and start a new chat.
2. Confirm that the voice input button is visible and working.
3. Continue using the same chat for several messages.
4. The voice input button eventually disappears or becomes unavailable.
5. Start a new chat.
6. The voice input button appears and works again.

Feedback ID: 019f805c-8d6f-7061-9b39-6a1f80fcbed2

What is the expected behavior?

The voice input button should remain visible and functional throughout an existing conversation, not only in newly created chats.

Additional information

_No response_