I am also having the exact same issue on a B550 Aorus Elite
I thought it was resolved when disabling XMP which crashed my OS entirely (I am running two 3600 mhz ram chips when my computer can only go to 3200 - if you get rare yearly corruptions of your OS and recovery states, it seems to be from XMP with the 3000 series mother boards)
But this issue still occurs. I only have a screensaver on, high performance mode activated, etc
If I leave my computer on, sometimes it just has no display output and is entirely unresponsive until I hard reset the PC. Thankfully I have a shutdown button on my unit and a hard switch on my power supply, but I can't find the issue and am concerned that hard resetting my device once a week is going to damage components eventually.
I've tried hunting through the Event Viewer log, done a Display driver uninstall and reinstall, Memtest 86+ with full 8 passthroughs, changed my NVME and reinstalled Windows 10 to update to Windows 11 - used Crystal Driver to review my lifetime statistics for ALL my drives.
My computers hardware is within three years AND all my tests are coming back totally fine - even the local computer shop can't figure out why this issue occurs - I have no unrecognized software as it's my gaming PC and I don't want to run the risk of getting malware, viruses, keyloggers, etc.
This must be something concerning with Windows 11's OS, since I can't see it being my PSU or GPU or my motherboard (which this problem occured on both the ORIGINAL bios install AND the newest Bios install) it's not my RAM or Hard Drives, and it's not my NVME's or SSD's.
If it were any of that, the computer wouldn't boot at all - does anyone have an idea of why a Windows 11 desktop could randomly freeze at times when leaving it on, say, when I go for work?