I am on PS4 Pro and play the game on a 4K TV with HDR on.
The frame rate does drop sometimes, bot in the game and in cut scenes, and sometimes the cut scenes have a "flash on and off" for about 10 seconds when they first load or transition.
In my hummble opinion, the PS4 Pro has some issues with HDR and NONE of the games I have that use HDR look as colorful as they should. All of them when HDR is activated look washed out. Really ticks me off. My new Xbox One X doesn't have this issue on HDR games. It's only the PS4 Pro.