Hey this is happening to me too. Can you help me?
I have a 4K OLED C7. Auto Dimming, etc is turned off, tried to lower the sharpness setting, didn't work. It only happens on my PS4 Pro and not XBOX one or any other EA Sports game. t only happens playing NHL 17 and NHL 18 that I just picked up.
In the offensive or defensive zones everything is fine, as soon as I exit towards the neutral zone everything dims temporarily.
ANY assistance would be appreciated. It is driving me insane. When going into the auto dimming sections and highlighting the off setting, everything is fine, but the moment I back out of it and return to the game, it goes dark.