Dear Samsung Member,
Greetings from Samsung Customer Support!
To resolve auto restart issue please follow below given steps:-
Go to Settings > General management > Reset > Turn off auto start.
If the issue still persist, kindly register your concern in Samsung Members app (Samsung Members app > Get help > Feedback > Error report/ask question).
Note: Please send device log files within 15 minutes of issue occurrence along with the exact issue details.
Thank you for writing to Samsung.
Samsung Customer Support