Unfortunately, we don’t have the MU8000 anymore as we only keep TVs for a year. To enable 4k @ 60Hz @ 4:4:4 + 8 bit HDR, you will need to turn on HDMI UHD Color and set the input icon to ‘PC’ (Otherwise, Chroma 4:4:4 will not be properly displayed). We were able to activate HDR in Destiny 2 (Video -> Additional Video -> HDR = On) on our MU9000, but it was very inconsistent and we have heard of a large amount of issues regarding HDR in Destiny 2, so it is not unlikely that the problem is caused by the game and not by your TV if everything else work. Have you tried other games where HDR worked?

I have same problem with KS8500. enabling HDR in PC mode doesn’t change gamma to EOTF and colors to dci-p3(still srgb range). And new windows and nvidia drivers update makes things even worse, it enables rgb 8bit hdr by default and KS8500(even in game mode) only changes gamma curve to HDR and forgets change colors to dci-p3. I need to change game mode to pc mode and return to game mode to return accurate colors.I guess, our TV have bug with rgb hdr.