I am seeing a lot of crashes in the i915 kernel driver in your kernel
log like:
May 28 15:54:36 nix-us2ua34705wc kernel: Call Trace:
May 28 15:54:36 nix-us2ua34705wc kernel: intel_atomic_commit+0x2b8/0x2f0 [i915]
May 28 15:54:36 nix-us2ua34705wc kernel: drm_atomic_commit+0x4a/0x50 [drm]
May 28
Thanks for all that. It appears the problematic monitor is:
VGA-1 connected 1200x1920+0+0 left (normal left inverted right x axis y axis)
519mm x 324mm
1920x1200 59.95*+
My first suspicion is that "VGA" is the first problem there. The
overdrawing of letters/pixels suggests a signal or
