Interesting electrical noise issue not the KVM’s fault but something for people to be mindful of.
As part of cable management I had a lot of wires cramped up in an Ikea wire shelf thing, an incandescent desk lamp cable was in there a long with DP cables, USB cables etc. Turning the light on/off would cause the smaller monitor to blank out for about 2 seconds then recover. Sometimes with power on, but 100% when turning it off (maybe an inductive kick creating a magnetic field in the 115v lamp line affecting DP signal to the monitor?).
Not sure if this is exacerbated by the fact my 970 dictates I use a DVI to DP adapter for the second feed into the desktop input of the KVM (maybe weaker DVI signal, maybe weaker signal out of the KVM, I didn’t trace the nest of wires the lamp 115vac ran by).
Anywho, when troubleshooting odd issues with your monitors, check for high power lines next to sensitive signal lines.
Typical Level 1 issue, its always layer 1!! I know I know, this isn’t networking though…