Reported by @craggy adder
Bug Report: ChatGPT 5 Thinking no reasoning at all and falls back to 4.1-like
`Steps to Reproduce`
Just use it on one of my device.
`Expected Result`
An output with reasoning appearing first.
`Actual Result`
No reasoning at all. If I ask it "what model you are" it tells me GPT4. If I'm using it on another device or on Android app then it works normally. If I switch on deep research, it only appears as a regular result with web search.
`Environment`
Linux x64, Firefox 142