temporarily change contrast to 99 or 98.Had my first experience or raised/flashing Blacks on the TV.
A good scene for it is in the movie "Black Box" on prime video. Minute 15 onwards. I lowered brightness to 49 and it fixed it. Not leaving my brightness at 49 though as that will cause more issues in general viewing than it fixes in near black scenes.
Can calibration fix this also?
Edit: Just to say this was HDR and not Dolby Vision.