My apologies. Nothing I read in your OP indicates that you assumed it was a notification (which could be from any/every application running on your PC!) that kept waking your monitor.
Well, some executable/application/program has to send a notification? Right? The "Focus Assist" notifications have never affected my screen-time outs or screen savers. If you can think of any other ways "notifications" appear and can be traced, please enlighten me.
EDIT: Looking at those notifications, each one is very descriptive of what is sending the notification: Microsoft Store, Google Chrome, Windows Security, etc... if it were that easy, I don't think I would have created this thread.
EDIT2: Disabled notifications completely and will see if that yields any results.
EDIT3: If that were the case, however, I have never disabled notifications, and for months this problem has not been happening, just after I updated...
EDIT4: I seem to recall sitting down at my monitor-off computer, jiggling the mouse, seeing the lock screen, then notifications will appear, yes, but it has never woken the screen before.
EDIT5: It seems "ShellExperienceHost.exe" is the executable for Notification/Action Center and I can verify it was running in my process tree for the duration of my 40 min 3GB log file, but it had 0 events associated with it.