It would be great if they at the very least have the courtesy to tell us they are looking in to this. Have anyone tried to contact Rockstar? Is there a forum?Set your output to 1080p maybe? Don't have a 4K set so maybe someone can chime in who does.
Well, I played for a few hours on a 23 inch 1080p monitor and downsampled looked so much better than the basic image, maybe because of the inherent sharpness to PC monitors and better pixel density. Went back to my 42 inch TV, doesn't look as good.
'Weird stuff is going on' is probably the best summation for this game. Seems to be all over the place in terms of checkerboard, HDR and SS implementation.