Auto restart

Unfortunatly the feature is removed after one ui 5 update.now you can't set time to auto restart. However you can enable auto optimisation from battery and device care and your phone will restart when needed

Dear Samsung member,

Greetings from Samsung customer support.

Thank you for sharing your concern. We acknowledge your query and apologize for the same. And please follow the easy troubleshooting steps which might help to solve the issue.
Kindly use a genuine Samsung charger.

Note: We always recommend using a genuine Samsung charger for charging your device.
There are two methods to enable the auto-restart function
Method 1

Please follow the below steps:
Step1: Navigate to the app's screen and tap on Settings.
Step2: Tap on General management.
Step3: Tap on Reset.
Step4: enable Auto restart (if disable).
Step5: Auto-restart enable .

Please follow the below steps:
Step1: Go to "Settings"
Step2: Tap on "Battery and device care"
Step3: Tap on Three dots
Step4: Tap on "Automation"
Step5: Disable "Auto-restart at set times" if disable

In case the issue still occurs. Please register your concern in Samsung Members Application (Open Samsung Members Application > Get help > Send Feedback >Error report).

Thank you for writing to Samsung.
Warm regard,
Samsung customer support