I'll assume that I am the only one with this problem, but if not I'd like to provide more information about my set-up. My set-up:
I have a 25 ft monoprice cable directly connected from the projector to my Onkyo
TX-NR656 receiver's MAIN port. The receiver has several HDMI 2.2 ports. I watch 4K content on my Roku Premiere+ which is connected to one of the HDMI 2.2 ports and my AppleTV 4K which is connected to a different HDMI 2.2 port; the screen going black happens on both devices.
The monoprice cable is this:
Monoprice Certified Premium High Speed HDMI Cable, 4K @ 60Hz, HDR, 18Gbps, 28AWG, YUV 4:4:4, 25ft, White
the HDMI cables that connect the device(s) to the receiver are also the Monoprice Certified Premium High Speed HDMI Cables found above but they are 6 ft in length.