iPhone 13
iPhone 13 pro won't auto dim. Screen stays bright all time
iPhone 13 Pro
Question marked as
Two things to check:
Settings>Display&Brightness>AutoLock.... (adjust its time, if needed)
or
Settings>Accessibility>Display & Text Size>Auto Brightness.... (the last option at the very bottom) = ON
When done, resatart your iPhone and test it.
Regards
Giulio