Unable to change reasoning effort #18624

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

26.415.40636 (1799)

What subscription do you have?

Pro

What platform is your computer?

Darwin 25.2.0 arm64 arm

What issue are you seeing?

When starting a new chat in the context of a project, I am unable to change the reasoning effort. I can click on the reasoning effort drop-down and can click on a different effort level, but nothing then changes.

What steps can reproduce the bug?

Uploaded thread: 019da932-70ec-7961-89a9-eb745c289263

Step 1: within Codex, to the right of a project name within the left-hand panel, click on "Start new chat in ".
Step 2: beneath the prompt input area, there is the reasoning effort selector which will be "Medium" (or potentially something else by default). Click on "Medium" and in the drop-down selector, click on something else, such as "High".
Step 3: Observe that the reasoning effort still says "Medium".

What is the expected behavior?

When clicking on the current reasoning effort level and selecting a different effort level, I expect that the reasoning effort level shown below the pormpt input area shows the newly selected reasonging effort level and not the remain unchanged.

Additional information

No response