I’m doing absolutely nothing and the phone makes a notification noise. But when I go check what it’s about there are no notifications in the drawer.
My phone is not rooted, I do the regular updates on time, and it can do it’s not a battery notification since it does it with the battery at 27%, 51% and whatnot…
Have you taken a look through the apps notification list to find out if there are any apps with individual notification set other than “off”?
Just for exclusion.