I would generally say this looks like problems more in kernel and firmware land, than bugs in the xserver driver to me...
I would, generally note a lot of wider AMD instability/issues (that Alan) talks about improved a lot in 5.8-ubuntu and 5.10-debian (bullseye and buster-backports) kernels. Even 5.4-ubuntu kernels still have problem with some newer Ryzen systems. In short, I'd recommend testing debian buster-backports version of linux-image-amd64 linux-headers-amd64 and report back on this bug. In particular -- can this bug now be closed, anyhow? How could debian warn users to update BIOS/firmware? --Simon
