BUG Codex Windows 404 Not Found Model not found gpt-5.5

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

5.5

What subscription do you have?

20 €/mois pour ChatGPT Plus. Votre compte affiche actuellement "Compte personnel", pas Business. Les fonctionnalités visibles (projets, tâches, GPT, Codex) sont cohérentes avec ChatGPT Plus.

What platform is your computer?

"$([Environment]::OSVersion | ForEach-Object VersionString) $(if ([Environment]::Is64BitOperatingSystem) { "x64" } else { "x86" })"

What issue are you seeing?

Codex Windows freshly reinstalled.

Any new chat fails immediately with:

404 Not Found
Model not found gpt-5.5

Endpoint:
https://chatgpt.com/backend-api/codex/responses

Issue reproducible on a brand new conversation with the single message "hello".

Reinstallation did not solve the problem.

Request ID:
dfdea00e-d5f3-4d53-acd0-16e9188afbd2

What steps can reproduce the bug?

Feedback ID: 019ef92e-12c3-7340-ba89-177c46b7dbb3

What is the expected behavior?

je voudrais ouvrir CODEX à nouveau ...

Additional information

_No response_