On my Samsung S8+ after updating Android to v.8.0 the issue "Always On Display Always Turning Off" solved by uninstalling all updates for "Always On Display" appl (go to Play Store to do this). Thereafter the application automatically updated to the latest version but the issue has gone completely.
No other ways to solve it helped.
A5 2017. I had this trouble and noticed that it was happening at the same time of day every day. GO TO THE ALWAYS ON DISPLAY SETTING, TURN IT OFF THEN BACK ON. Somehow it was running to the schedule that you see when you turn it off, even when it was turned on! Noticed soon after Oreo update.
I FINALLY found a solution after countless worthless posts trying to fix this problem! If you have the Talkback app, turn it OFF or unistall because that was what interferedwith my ALWAYS ON DISPLAY even though it was turned on!
No solution found. Accepted solution is incorrect for a brand new undamaged phone or for a phone that has no cracks in the screen.
After latest update, AOD no longer stays on, but shuts off after random intervals of inactivity. In other words, it could be after being idle 5 minutes or 3 hours. This problem did not exist until after the latest update, April 2018. Currently S7, Android 7.0, kernel 3.18.31-12142063, on T-Mobile service.
Just a note, every update has also caused keyboard swipe to continuously get worse and worse as well causing auto-correction to spell non-existent words. Example, "then" congress up as "thrn" and swipe for "in," "I'm," "on," etc, to leave only an I...
A real solution would be appreciated.