screen randomly blanking on 4k with hdmi, onboard intel graphics card

[pixel fairy]

qubes-os 4.0 system76 lemur7 (i7 skylake) the hdmi port seems to only work well at hdmi. any other resolution and it randomly blanks the screen. tried running the ubuntu (pop-os) installer for about an hour watching youtube and the screen was fine. dont know if that was luck or a qubes-os problem.

does anyone else do 4k out of hdmi with the onboard intel grahpics?