Yep, many reporting this issue. I did about a month back. This seems to have stopped working on Note 10s after the September security patching as far as I can tell. I even posted a review about this on the Galaxy store under AOD app to let developers know but no fox yet.
It sucks because it is even on when in your pocket. Which is stupid.
I was able to find this app aodNotify.
https://play.google.com/store/apps/details?id=com.jamworks.alwaysondisplay
LOVE IT. Gives you full control when your AOD should be on. So I have my AOD to tab to show but the app turns it to fully on when I get texts or missed calls, or Whatsapp texts. You can control when to turn it on app by app basis. Again, love it. Give it a shot.
I tried many and this one is PERFECT.