I turned off the WiFi and mobile data on my Samsung Galaxy Note 10+ at night but when I woke up this morning, the data was on. There's no chance that someone else might have turned it on and I do remember double-checking that it's off before I slept.
It is allowed for some apps but it's the same for Samsung Galaxy A52s. Other than WiFi sync off on Note 10+ and on on A52s, no other permission is different. Yet Note 10+ had it's data on the 2nd time in this month and this has never happened with A52s.