Windows Codex Desktop: Send button becomes disabled after the first successful turn

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

26.908.40834

What subscription do you have?

GPT Pro

What platform is your computer?

Windows 11 x64

What issue are you seeing?

On Windows Codex Desktop, a newly created conversation works normally for exactly one turn. After the assistant completes the first response, I can type a follow-up message, but the Send button remains greyed out/disabled and the second message cannot be submitted.

What steps can reproduce the bug?

1. Launch Codex Desktop on Windows.
2. Create a new conversation.
3. Send ping1.
4. Wait until Codex successfully responds.
5. Type ping2.
6. The Send button is disabled, so the follow-up cannot be submitted.

What is the expected behavior?

After the first turn completes, the composer should return to an idle/ready state and allow another prompt to be submitted.

Additional information

Actual behavior:
The first turn completes successfully, but the composer/send state does not recover. The Send button remains disabled for subsequent turns.

Important isolation result:
Codex CLI on the same Windows machine, using the same account, model, project and network connection, successfully completes 3+ consecutive turns. This suggests the issue is specific to Codex Desktop's conversation/composer state rather than the model or Codex backend.

Troubleshooting already performed:

• Fully terminated all ChatGPT.exe and codex.exe processes and cold-started Desktop — still reproduces.
• Changed Follow-up behavior from Queue to Steer — still reproduces.
• Created new conversations — still reproduces.
• Codex CLI multi-turn conversation works normally.

Environment:

• Windows
• Codex Desktop: 26.908.4834.0
• Model: GPT-5.6 Sol, Medium reasoning
• Network uses Clash Verge/Mihomo with TUN enabled. However, Codex CLI works normally over the same network path.

Potential area to investigate:
The Desktop client may not be resetting the composer/turn state after receiving the completion event for the first turn. It would be useful to check whether the renderer still believes a turn is active (isSubmitting / isRunning / active writer state) even after the backend turn has completed.

Reproduce the issue in Codex Desktop on Windows using the documented two-turn steps, then trace the renderer's completion handling and the isSubmitting, isRunning, and active writer state mentioned in the report. Compare Desktop's state transition with the working multi-turn Codex CLI behavior. Done means the composer returns to an idle state and the Send button accepts follow-up prompts after the first response.