Comment # 6 on bug 1232718 from Timoth York

I did a little more digging, and I'm almost positive now it's a bug in the
amdgpu firmware. I downloaded the old version
(kernel-firmware-amdgpu-20241010-1.1) from:
https://download.opensuse.org/history/20241018/tumbleweed/repo/oss/noarch/kernel-firmware-amdgpu-20241001-1.1.noarch.rpm
and force installed it:

$ sudo zypper install --oldpackage
kernel-firmware-amdgpu-20241010-1.1.noarch.rpm

and selected option 3 (break kernel-firmware by ignoring some dependencies)

Everything seems to back working correctly, at least in KDE now. I've
temporarily locked it for now:

$ sudo zypper al kernel-firmware-amdgpu

If this works for you, maybe we should close this bug and refile it under
Kernel or Kernel:drivers? If it really is in the firmware, I'm not sure how
that gets propagated to AMD, as I'm pretty sure the actual firmware code is
closed source, and just the blobs get posted to kernel.org.