I have the same problem on gentoo with 5.4 kernel and mesa-git, so it's not
only arch and ubuntu, it's all distros. But I didn't create an account before,
because I thought there were already enough comments which confirm the bug. I
hope this can be fixed soon because it's really annoying, tell me if I can help
with anything.

I think the powerplay/metrics error is a different bug, I saw that too on my
system, but not that often and unrelated to the freezes (so way less annoying).