( 2 years later, lol )
For anyone still having this problem, see if the following will help ᎓
・ go to Settings ▸ Display and look for Adaptive brightness ; if it's enabled then that was the problem, but go ahead and complete these steps regardless of whether it was enabled or not
・ if Adaptive brightness is enabled, do this ᎓ disable it, then enable it again ; if it was disabled in the first place, just enable it ( it should now be enabled, regardless of which group you were in )
・ tap the setting itself — not the button, the words "Adaptive brightness" themselves — to access a submenu
・ tap [ Reset usage patterns ] button, and confirm
・ immediately turn off ( disable ) Adaptive brightness
・ restart the device, just to be sure — can't hurt, might help
If you had Adaptive brightness turned off in the first place, as was my case, then on the surface it looks like none of this should be needed ( nor should it do anything, for that matter ), but that's the whole problem, isn't it — the device acting like Adaptive brightness is ON even when it's OFF. That being the case, what this does is ( i.) clear out any and all learned adaptive brightness rules and ( ii.) power reset the Adaptive brightness feature.
I posted this because it did work on my S8+, so I know it can work, but as for your own case I would say it depends, because there are other factors at play, such as your particular device model, whether your model has an adaptive brightness setting in the first place ( lol ), and whether you have another setting ( or possibly even an app ) that can influence display brightness . . . so just give it a shot and hope for the best.
08-14-2019 05:58 PM