Reasoning level doesn't change for new 'Chat' threads

[zdaman101]

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

Version 26.415.30602 (1773)

What subscription do you have?

ChatGPT Pro

What platform is your computer?

MacOS Darwin 25.4.0 arm64 arm

What issue are you seeing?

Whenever I create a new Chat thread, it defaults the last used reasoning level to the thread. If I attempt to change it, the dropdown opens, I can select a different reasoning level, but it doesn't show the new reasoning level when the dropdown closes.

Feedback ID: d162698b-b968-49b1-8305-4b5deabc5051

In the above image you can see that the current reasoning level when the new chat thread popped up was 'Extra High' and I am attempting to select 'Medium'

After selecting medium the dropdown closes but the "selected" reasoning level stays at 'Extra High'.

What steps can reproduce the bug?

Uploaded thread: d162698b-b968-49b1-8305-4b5deabc5051

• Click New Chat (Opt + Cmd + N)
• Before submitting a prompt attempt to change the reasoning level
• Once the dropdown dissapears, the reasoning level will not change

What is the expected behavior?

Upon selecting a new reasoning level from the new chat's dropdown, the reasoning level will change to the selected reasoning level

Additional information

No response

[github-actions]

Potential duplicates detected. Please review them and close your issue if it is a duplicate.

• New conversation ignores selected model and starts as GPT-5.4 #17933
• can't change model and reasoning efforts sometimes #17318
• [BUG] Can't switch reasoning effort to Xhigh in Codex app #17328
• model_reasoning_effort from config.toml seems overridden by last-used reasoning on fresh CLI launch #17436

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[zdaman101]

This is still an issue as of version 26.417.41555 (1858) on 4/22/2026. Likely a duplicate of other items as pointed out by the bot, but one of the duplicates mentions during the creation of plan mode and another was referencing the CLI. I am experiencing in the Mac Desktop App and it only occurs when starting a new Chat. New threads under Projects works just fine. I should also mention that it defaults to whatever the last selected model & reasoning was for a chat, even if it was 1-2 days earlier. Super annoying when I want to use GPT 5.4 mini on Medium reasoning but it defaults to GPT 5.4 on High reasoning.

[pomazanbohdan]

019df716-28d8-7ef1-a019-7529cb303c27

[pomazanbohdan]

This has already been fixed in today's release
@zdaman101 test pls