Garmin has acknowledged a bug that leaves the Fenix 8's AMOLED screen stuck at full brightness after the watch has been in strong light. A company representative confirmed it in an October 7 reply on Garmin's support forum, Gadgets & Wearables reported, and said the fix is pending for the next software update. Garmin gave no date for that update and no version number. The bug shows up with Always On Display turned on and the wrist gesture turned off: the watch raises its brightness in strong light and then sometimes fails to dim when you walk somewhere darker.
Owner reports began with software version 23.31 and have continued on 23.39, so updating to the newer release doesn't reliably cure it. Until the fix ships, Garmin's advice is to tap the touchscreen or press a button, which returns the display to normal, and you may have to do that again each time the watch has been in bright light. If your Fenix 8 is losing charge faster than usual, check whether the display stays bright after you come in from outside. Garmin hasn't said how many watches are affected or published a list of affected models, and it says it will post in the forum again when it has more to share.