Is anyone still getting this issue with 12.1? I often get the notification and also experience a very unstable system with various app crashes. This did not go away with a completely fresh install (erase disk). For what is worth I’m getting this issue on a 2019 16’’, another 2019 13’’ I own is running fine.

I've been with this issue for a few months now. I've also downgraded to BigSur which now has other issues (notably multiple kernel panics per day: https://developer.apple.com/forums/thread/678644 and app crashes). Earlier in this thread people reported that this issue was due to a faulty RAM module, which I didn't believe initially. After I run a memtest86 test I'm now convinced that indeed I also have faulty RAM. In my case I have no option than a motherboard replacement as the RAM is soldered. So imo the error reported here is a symptom, and different versions of macOS show different symptoms (BigSur v Monterey). But the cause is most probably something hardware related, thus I'd recommend for everyone having this issue running a memtest86 test to check if this is the cause of their problem.