I just had this, for me it turned out that I needed to connect via cable to my Mac first, problem was I was using a third party cable. As a last ditched effort I dug out my apple cable (usbc-usbc) That did the trick I got all the prompts for trusting the device and then the Developer Mode option popup in the settings.

I have started hitting this. Really annoying, it started with forcing me to start new conversations but now has the 24h limit even when signed in to ChatGPT in system settings and Xcode. I tried the steps above which made no difference. Xcode Version 26.0 (17A324)