Atic,
I'm using a Samsung KS8500. I calibrated the TV for HDR based off of input from Rtings.com aside from a few minor tweaks.
https://www.rtings.com/tv/reviews/samsung/ks8500/settings
The in game settings are as follows:
HDR 10 TV Peak Brightness 16% (This is where the 2 boxes look exactly the same with no line on my TV)
Brightness 50%
I've tried lowering the brightness in game and on the TV. It only reduces the overall luminance, but the whites still look over saturated.
It seems this issue came with the last patch after the servers were down last week due to some issues. Its worked fine up until that point, but currently I've been playing this game with HDR turned off in my PS4 Pro settings and re-enabling it for other games due to this issue.