Apple watch brightness stuck on maximum

Hi all,

I have an Apple Watch Series 5, and two days ago when I put it on in the morning the brightness was notably higher than usual (blindingly so). I normally keep it on the lowest brightness setting, and sure enough the setting (on my watch, on the iPhone as well) is set to the lowest, but the screen is very bright. It does not dim any longer when in "passive" mode (i.e., when the second hand disappears, after a period of inactivity). Increasing the brightness to a higher setting does not increase the brightness further, and dropping it back down to a lower setting does not reduce the brightness.

I've tried (in this order):

Turning the watch off and on again alongside the iPhone

Forced reset of the watch

Unpairing and repairing from a backup

Unpairing and setting up as a new watch

None of these affected the brightness issue at all. To my knowledge, there was nothing unusual that happened to the watch the night this change occurred. It didn't update the software (I've been running Watch OS 6.2.8 since it was released with no issues); it wasn't physically damaged, or dirty, or similar.

Any ideas?? I can't figure it out and the brightness is driving me crazy...

-Mac