So I finally got around to resetting my phone, and just ran into the "screen not updating when screen turned on" IN THE SETUP STEPS! Anyone else getting this in apps? Again, the problem seems to be:
1. Open app.
2. Screen off.
3. Screen on.
4. Sometimes: App's screen doesn't update any more until you switch to another app and back (but still registers clicks/swipes as if the app were running fine, you just can't see any changes on-screen). Swipe down from top still opens the notifications panel but just opening that and going back to the app doesn't fix it. Going to Home and back or application switcher and back does fix it.
I've had this happen in Bumble, Tinder, OS Settings, Chrome (except there the web page goes black instead of maintaining the previous screen), Piktures (black screen instead of maintaining the image, like Chrome), Timely (where the countdown timer is still running, just the screen isn't updating to show that), Play Store, and Acrobat Reader.
In all cases, the app isn't actually frozen and you can still blindly take actions, you just can't see the result of those actions until you switch away and back.
Edit: I reset again and didn't restore anything to confirm that this wasn't related to any setting that was being restored and it definitely happens without restoring any settings. One app that was easy to test with was
https://apkpure.com/buck-legacy-calculator/com.turokevie.bucklegacy which exhibits the problem after just a few screen off-on cycles (pressing buttons makes the update sound but doesn't update the screen). Also I noticed that I had to completely disable the screen lock to have this problem, since the Swipe to Unlock setting presents an app screen (the swipe screen) when you turn on the screen and thus has to switch to the previous app when you swipe, avoiding the problem. But I hate having to swipe to unlock.
Also confirmed that these 2 bugs weren't due to my phone settings:
TextNow and 2nd Line phone apps don't work on wireless data, only on WiFi (can send and receive texts but outgoing and incoming calls don't work at all).
Grindr also won't use wireless data (chat's say Disconnected if you aren't on WiFi).
Seriously considering downgrading to Oreo.
