My screen can do 2560x1440 at 240 Hz with display port (ref : iiyama GB2790QSU-B1).
It's working with my old Nvidia gtx 1070, I can see all possible resolutions. Not with my new rx 7900... stop at 2560x1440 144 Hz (have 1080p 240Hz).
All drivers / os are already updated, same on 2 computers.
My settings :
Windows 10 pro 22H2
Graphics drivers 22.12.2
Guess it's a driver issue
Same on a fresh install and Windows 11
Same here. It is driver bug.