Note 20 5g keeps resetting

[Peteloafer]

Acquired from Ama#on refurbished item. Resets at least 3 or 4 times a day sometimes when I'm not doing anything and sometimes when several windows active. Will return if I can't fix this.

[BaronDigo]

Return brother.

[BandOfBrothers]

You can try options such as > Clear Cache Files from the phone's System Partition Section > https://www.samsung.com/uk/support/mobile-devices/how-do-i-clear-the-cache-on-my-device/ You may need to insert your earphones or hook upto a powered On Laptop to access the Clear Partition Section. This may help with lag or stutters as this clears the phone of old/unused or broken cache files.There is also a Repair Apps option in the Menu System too.
However I'd agree to return the phone stating it is faulty.