I originally went to submit this via support. But there’s a back end issue causing the page to error when submitting the report. So I’m posting here.
HDMI 2.0 CABLE:-
I’ve been through a lot of troubleshooting.
New certified 4k60hz HDMI2.0 cables, 30hz, 60hz, 2k, 4k, via display settings in the OS and in game. vsync on or off. Both monitors plugged in and with just 1 monitor plugged in.
Lesser demanding games will be less troublesome. But the more demanding will make the display go black more frequently.
I got cheesed off with it and plugged the HDMI directly into the 1.4 port of my GPU and all the issues immediately dissapeared. All of a sudden I was able to play Witcher 3 in glorious 4k resolution (but locked at 30hz) absolutely fine, no issues at all. Which has made me realise months of intermittent tweaking was in vain as it was the CAC-1070!
I have a video of the issue if you would like to see it.
Do you have a firmware revision to fix the issue? Or is my display adapter faulty?