I have a big problem with my Samsung Galaxy s21. The phone is restarting the whole time..and sometimes apps don't work. After I restart the phone the apps do work... also the phone freezes a lot and I get to see a black screen.. I think my android system is corrupt. I also installed the latest updates but after this the phone has still the same problems. I even did a complete factory reset but the problem still exist. What I can do to fix this annoying problem. I really appreciate your help.
Since a Factory Reset didn't resolve the issue, you might want to visit a Samsung Service Centre to get it checked out by a tech.
Only other thing, if you Restored your device after you Factory Reset, you could try a Factory Reset again, but this time, don't Restore anything, just start completely fresh.
If you still have the same problem, then really a visit to a Service Centre is the only option.
