The same issue was on the windows insider version where the desktop would freeze and become non responsive, but the pc with the smaller 1080 display would work fine. I think the problem is in the Memory Leak in the GUI and possibly a driver/ timing/Sync issue as i tried out the official release on my main PC which has the large ultrawide Monitor @ 3840 x 1200 and also a 34" 4k @ 3440 x 1440 and it seams to happen at random times. I had Vlcplayer open and the Chrome browser open on the Large Ultrawide and Adobe Photoshop open on the other and it started with VLC Player freezing first then i would lose the ability to be able to type as the cursor disappears. CTRL ALT DELETE Doesn't work and it won't close documents or save anything left open. I noticed they have released updated windows 11 drivers, but i had to go back to windows 10 as i needed to get some work done. Fo the time being i have to say don't update unless it is a secondary system. I have tried multple experiments by disabling programs at startup to see if that resolves, but it is a lot deeper issue Microsoft may have to patch. Microsoft Needs to Patch it as i haven't found a workaround yet.
My System
AMD 5950X
AORUS RTX 3090
ROG Crosshair VIII Formula x570
Corsair Vengeance RGB PRO 32GB (2 x 16GB) DDR4 3600MHz
Samsung 43" Ultrawide 120 Hz
Samsung 34" Ultrawide
Cheers