[Bug 107731] radeon (amdgpu) DisplayPort loss of max-resolution on DP monitor (after monitor power saving / idle)

https://bugs.freedesktop.org/show_bug.cgi?id=107731

--- Comment #12 from L.S.S. ragnaros39216@yandex.com --- Sorry, but should have commented on this much sooner.

After my last comment I eventually replaced the ATEN CS1924 KVM with a new generic 4-port KVM that is 4K@60Hz-capable. This one does not exhibit the issue, so I could consider my own issue as having been worked around. The new KVM costs about 1/4 of the ATEN KVM, though.

I'm not sure about the OP's situation or whether he had worked around or not, but this kinda proved that the issue is indeed configuration-specific.