Apologies… I’ve seen several posts about this issue but not much in the way of a solution. I’m running into a JVC 4k projector and I have CoreELEC 19.2-Matrix_rc2 running on a ODROID-N2. The native panel in my projector is 4096 x 2160 and this is the resolution I have Kodi set to output.
Generally, this setup gives a stunning picture but last night I was watching a UHD source. When I pressed play, I could hear the filter in the projector move into place so it was getting a BT.2020 HDR signal but the picture was very dark.
Does your projector properly support HDR input signal?
Projectors can’t really get bright enough to display HDR properly. And depending on how well your projector handles tone mapping, the content may either look too dark, have very little highlightst (anything bright will look blown out) or any other combination of poor viewing experience.