Codex Desktop: Pro/Fast reasoning option disappeared from GPT-5.5 picker

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

Codex Desktop 26.623.42026, build 4514

What subscription do you have?

ChatGPT Pro

What platform is your computer?

macOS

What issue are you seeing?

The Codex Desktop model/reasoning picker no longer shows the Pro/Fast-style
reasoning option that was visible until a few days ago.

For GPT-5.5, the picker now shows only:

• Low
• Medium
• High
• Extra High

I submitted in-app feedback for this report:

019f09b5-971c-71e0-b56d-8d2e46c928c9

The issue may be related to a server-side rollout, entitlement/UI regression,
or a deliberate rename/removal, but I have not found a changelog or docs page
that clearly explains the expected Codex Desktop behavior for ChatGPT Pro users.

What steps can reproduce the bug?

1. Open Codex Desktop on macOS.
2. Sign in with a ChatGPT Pro account.
3. Open a workspace or thread.
4. Open the model/reasoning picker.
5. Select or inspect GPT-5.5.
6. Check the available reasoning options.

What is the expected behavior?

If the Pro/Fast-style reasoning option is still supported for ChatGPT Pro users
in Codex Desktop, it should appear in the picker.

If it was renamed, removed, moved, or limited by rollout/account eligibility,
Codex should make that clear in the UI or docs so Pro users know whether this
is expected behavior.

Actual behavior

The picker only shows Low, Medium, High, and Extra High. The previously visible
Pro/Fast-style option is no longer present.

Additional information

Related public report:

• https://github.com/openai/codex/issues/29293

Official docs I checked appear to distinguish between gpt-5-pro as an API
Responses model and Codex Desktop model/reasoning choices. I do not see a
current public explanation of whether a Pro/Fast-style Codex Desktop reasoning
option should still appear for ChatGPT Pro users.