Sounds like you have Auto-Brightness on, and the brightness will change based on the ambient lighting. See this to turn off the setting if you wish. Go to Settings>General>Accessibility>Display Accommodations>Auto-Brightness.
Apple Event: May 7th at 7 am PT
Newsroom Update
Apple is introducing a new Apple Watch Pride Edition Braided Solo Loop, matching watch face, and dynamic iOS and iPadOS wallpapers as a way to champion global movements to protect and advance equality for LGBTQ+ communities. Learn more >
Apple is introducing a new Apple Watch Pride Edition Braided Solo Loop, matching watch face, and dynamic iOS and iPadOS wallpapers as a way to champion global movements to protect and advance equality for LGBTQ+ communities. Learn more >
Sounds like you have Auto-Brightness on, and the brightness will change based on the ambient lighting. See this to turn off the setting if you wish. Go to Settings>General>Accessibility>Display Accommodations>Auto-Brightness.
Inconsistent Brightness