@Cristian9806: Further to the above, if Auto optimisation is not enabled, please try restarting your S21 Ultra in Safe mode, as this will disable all third party apps, and help to determine if the problem is stemming from an external source. To enter Safe mode, press and hold the Power button until the 'Power off' prompt appears on the screen then release > Touch and hold Power off until the 'Safe mode' prompt appears then release > To confirm, tap Safe mode.
While in Safe mode, check to see if the restarts continue to occur. If not, restart the phone as you would normally and uninstall any apps that you have added to the device since you first encountered the problem.
