There’s been a couple hiccups when it comes to the move to DX12/SM6 only for some of the new tech and I’ve seen a myriad of possible issues. Most of them being environmental in nature. I’ll dig up some threads and info for you to glance at, most of it won’t pertain 100% to your issue or VSMs but they are related by the thread that specifically drivers or their setup can fix. To give you a short rundown of a couple that I’ve worked through with other users:
Do you use anything like iCue, Rivatuner, MSIafterburner, or any GPU touching overlay? These can sometimes cause all sorts of rendering artifacts, usually culminating in crashes.
Since you reinstalled your drivers, you may need to reset the settings for them as well (they tend to persist between installations). My frame of reference is Nvidia here so not 100% comparable, but resetting the settings for the card has solved this issue numerous times.
You can check your system’s DX version by running the dxdiag in your windows search. It’s likely up to date though, so it’s often drivers themselves causing issues.
Lastly, I’m seeing a rise of issues now with VSMs and 5.1.1 but couldn’t find a corresponding bugfix that could have made it happen. Some users are Win10 and some Win11 so I don’t think it was a windows DX shift.
Try shifting the bias like this thread here, if it doesn’t effect it at all, you may need to turn of VSMs while this gets sorted if it is indeed an engine bug.