Is the phone restarting at the same time as this is a setting in the phone that can be turned Off.
Restart-your-galaxy-phone-regularly-to-prevent-it-from-slowing-down-or-freezing.
But if it's restricted at different times then you can troubleshoot the phone.
- 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.
- Safe Mode > https://www.samsung.com/uk/support/mobile-devices/how-to-start-my-galaxy-device-in-safe-mode/ turns off downloaded apps and themes etc which may highlight an app or theme that's causing conflict.
- Run the diagnostic tool in your Samsung Members App.
- Back up and factory reset but don't use the back up when setting up the phone again and then see what happens.
- If any app has been downloaded via an apk file then don't reuse it.
- Ensure your phone's software and apps are up to date.
If I can be of any further help then please don't hesitate. Take care. 😎
Daily Driver > Samsung Galaxy s²³ Ultra 512Gb in Phantom Black.
The advice I offer is my own and does not represent Samsung’s position.
I'm here to help. " This is the way. "