Has anyone with the issue tried this update by chance (or made sure it's installed?)? https://www.bleepingcomputer.com/news/microsoft/windows-10-kb5000842-cumulative-update-fixes-freezing-issues/
I had the freezing problem when I had moved forward from 2004 to 20H2 and then I rolled back to 2004 and the problem went away - I'm still on 2004 and I won't install a new version until 21H2 later this year, but I am continuing to monitor this thread as this is a very concerning problem. Hoping an actual solution is found at some point since some people who have now tried 21H1 are still having some issues as well.
EDIT - Also has anyone tried disabling "Hardware Accelerated GPU scheduling"? I saw one post on reddit where someone had mentioned that resolving system freezes for them. So just something to try. Since I am not currently having the issue with v2004 I can't test any of this stuff.
I've just checked and I did install that update and currently running the latest 21H1 version of Windows and I had 6 lock-ups just from yesterday.
I disabled the Hardware Accelerated GPU Scheduling since version 1909 and didn't have a luck with it.
Good thing that you don't experience any issue after you rolled back because I read on another thread that someone rolled back to version 2004 and the problem didn't go away. Rumors has it that the next major update would come out at the end of July this year and I am not sure if it's going to fix this issue. Hopefully it will because I can't trust my laptop with any important work at all because of the freezing issue.