XR Brightness issue
I use my iPhone for work while driving and the brightness dims sometimes when I need it most. The brightness control doesn’t do anything, it shows that it’s as bright as it can be. How can I keep the display bright?
iPhone XR
Disable automatic brightness in Settings>General>Accessibility>Display Accomodation.
If you want, you can also adjust the Auto-lock time in Settings>Display&Brightness>Auto-lock... to "never".
The above procedures will affect your battery drain, so use them only if strictly needed.
Regards
Giulio