OK...
You don't think it could be any of DiskUsage, SD Maid, FairEmail, and Clean Cache? Clean Cache seems like the most likely, so if it's that I must have yet another look for an app to do this. I had Norton Clean for a long time but became unhappy with it lately. My thinking was based on an article I saw (can't remember where) about similar problems, and the apps mentioned were all hibernation/battery saving type things, and cache/junk cleaners.
Come to that, the only permission I've taken away from anything is uninstalling Norton Clean, but that couldn't do this, could it?
I have a Sudoku game which is heavy on battery, but again... that wouldn't be delaying notifications, would it? Could it? When the game is hibernated all the time that I'm not using it?
The only native "battery app" I can find is the one that turns on battery saver at 15%, and I've just found that it's disabled anyway (can't remember doing that but it can't be causing this... can it?).
I'm happy to type out a list of every single app on the phone for your perusal, if it comes to that! Well, maybe happy is the wrong word.
im even running the beta Ui from samsung and am still having normal operation. meaning apps are notifying me.
They are notifying me - eventually, Late or unbelievably late, that's all. Feels like a problem in the system rather than anything I installed, because even the native clock isn't sounding alarms on time - at least that's my layperson's reasoning. Sometimes when I set an alarm and it doesn't happen, it's still there but moved fowards by 24 hours. I mean that if I set it yesterday evening for 6am today, as a one-off (non-repeating) alarm, then when nothing happens and so I look today, it's still 6am but for tomorrow. Perhaps that's a clue...
I will go through *all* settings as soon as I can, see what looks odd. Pretty sure I haven't changed any in the past few weeks, though.
you can also clear the system cache that you have access to on the bootup screen....
I've been doing this with apps, such as Clean Cache or previously Norton Clean. I've just found how to clear cached data, in the phone's Storage settings, so I'll uninstall Clean Cache now... (oops, didn't know I could tap on that list). (Now that I have cleared cached data, it still shows as 2.54MB, which I presume can't be deleted.)
But how do I access that from the bootup screen - should I press something while the phone is displaying "starting app 6 of 90"? I didn't know I could do anything but wait through that.
Anyway, I'll give it a day to see if deleting Clean Cache has done the trick. If not I'll be back.