Hi, up to this day, I haven´t solved the video quality and shine problem in UE, but this helped:
I turned OFF bloom… sadly If I press G to previsualize… bloom turns On again… and indeed causes some weird brightness
I turned OFF Eye adaptation, this I HATE… it causes this ultra brightness when you are moving the camera, no idea why this even exists, when I jump in a parachute, I never have “eye adaptation” LOL… no chance, unless I keep staring to an strong light directly for 30 seconds, maybe… but it causes my video to have an extra layer of white tones.
After that, my video was still looking weird in the image plane, white colors look bright, some colors look in different tones, and it is playing the video more in 1K quality than 4K with some pixelation, so… there was no choice, I had to go back to my editing program and make those scenes darker and reduce color intensity, now it looks better… still, never as good as in my video players