I guess the Q90T actually tries to make subtitles darker during dark scenes in an aggressive attempt to reduce blooming. Sometimes these subtitles can get so dark they become difficult to read and sometimes the algorithm gets confused and subtitle brightness will fluctuate between bright and dark somewhat rapidly even though the brightness of the scene isn't changing.
I find all of this to be MASSIVELY more distracting than the blooming the TV is trying to prevent by doing this. I would gladly enable an option to prioritize subtitles appearing consistently bright, even if it meant I would get blooming.
If there's any way to fix this, I would love to know. If there isn't, I would love to see an option like this added in an update and I know I can't be the only one.