Dear Samsung Member,
Greetings from Samsung Customer Support!
Kindly ensure that the auto-restart option is turned off. Perform the following steps to turn off the auto-restart issue:
Settings > General management > Reset > Auto Restart > To set the time of the restart, touch Time > Set the desired time and then touch DONE > To set the day of the reset, touch Day > Select the desired day of the week (For this example, select Every Friday).
To improve device performance:
1) Check space availability: Settings > Device Care >Storage. (Minimum 20% internal memory free)
2) Clear app cache through Device care: Settings > Device care > Storage > Clean now.
For more steps kindly visit the link given below:
If the issue still persists, kindly attach the log file and send it to us in the Samsung member application (attach when the issue occurs within first 15 minutes): Samsung Members App > Feedback > Error Report > Attach log file.
Thank you for writing to Samsung.
Samsung Customer Support