This morning, when i switched from 1 monitor to 2 monitors i had a flashing black screen on 1 monitor. The same monitor has flashed on and off a few other times, but i don't recall the specifics of the timing. The configuration . Monitor 1 (flashing one) displayport 60 hz 4k. Monitor 2 displayport 100hz 3440x1440. Monitor 3 (off and not being used when this is happening.) HDMI 4k 120 hz. It is always monitor 1. Restarting displayfusion didn't stop it. On 2 occasions i have unplugged the power from the monitor and plugged it back in then it works. I have attached log but it doesn't seem to have any significance. The monitor 1 and 2 cable and monitor configuration has worked for years without issues. Added 3rd display maybe 2 months ago.
One last thing.. Monitor 2 is plugged into another computer as well with hdmi and this might be happening after monitor 2 is in standby and powered back up and then switched to display port but im not sure that is always the case.