months ago I set my S10 to make a sound when battery is 100% [Setting -> Notification -> See all -> tap 3 vertical dots on the top right below the camera hole -> select 'System UI' -> Battery full]. It works for a while, but recently I just noticed that it never made a sound like usual. Btw. I used the custom notification sound that I downloaded from the app 'Zedge'. I tried using pre-installed notification sound i.e. Spaceline, but it didn't work either.
Second problem that I had is that my S10 no longer shows the green battery icon on AoD when battery is fully charged.