Since H.264 isn’t used for any commercial 4K material, plus the fact that the black bars have been cropped (3840x1608) tells me this is a re-encode of a UHD BluRay.
It’s likely an incorrect re-encode that doesn’t correctly convert the HDR to SDR, so colors will be washed out. Also, the video stream also doesn’t contain information about the color matrix to use, so it would be assumed to be Rec.709, not Rec.2020, which will also cause an incorrect display.