Created attachment 850887 [details]
dmesg from 5.12.13 kernel & first radeon DDX instance, then modesetting DIX
instance
Still happening with TW20210706, plasma5-desktop-5.22.2.1-1.1 &
kernel-default-5.12.13.
This PC has two entirely separate 20210706 installations, one with only IceWM
and Plasma, the other with only KDE3 and IceWM. Only using Plasma session
causes this.