[Bug]: After receiving the first answer, changing the reasoning effort changes the model to GPT-5.4

[fgonzalezurriola]

Before submitting

• I searched existing issues and did not find a duplicate.
• I included enough detail to reproduce or investigate the problem.

Area

Not sure

Steps to reproduce

1. Send a message with GPT-5.4-mini with any reasoning effort
2. Wait to response
3. Change the reasoning effort

Expected behavior

Stay in GPT-5.4-mini

Actual behavior

The model changes to GPT-5.4

Impact

Minor bug or occasional failure

Version or commit

0.0.15-2

Environment

CachyOS x86_64

Logs or stack traces

I couldn't launch the app with cloning the repo, sorry Julius. I don't have logs or traces
Please I use mini on xhigh to explore, the normal one consumes a ton of usage. Also I'm not sure if this is a UI problem or if actually does the request with 5.4 
This doesn't looks to happen after the first prompt, but It happened with 5.3 and changing the reasoning effort

I can't afford spending more quota investigating this sorry about that
The video i uploaded looks a little weird sorry about that too

Screenshots, recordings, or supporting files

t3code_clip.mp4

Workaround

No response

[fgonzalezurriola]

Okey I'm finally fixed the postintall thingy...

I noticed that happens with every model only after the first response. I will rename the issue

Tomorrow i will look to the code! I hope

i think this bug consumed a lot of my $20 quota sadly, i use a lot mini xhigh for exploring. Gladly i noticed this early

2026-04-08_22-44-36.mp4