Phone is stock, operating it just like it came out of the box! This is my 3rd note 5 and it has done the same thing on the other 2 also! I tried it when I first got the phone turned on and operating before I downloaded all my apps and installed my email clients.
I am in same situation, seem like Setting>Battery>App Power Saving, and Setting>Battery>Battery Usage>Optimize Battery Usage,
both function seems redundant. I uninstall other battery app (GSM), but that doesn't seem to be the problem.
Hmm, I'm kinda stumped here. Is this a carrier-specific Note5, and if so, which one? Carrier-specific phones could have carrier-installed bloat that might mess around with these kinds of settings.