We would request you to register your concern in Samsung Members Application. So, that our concern team gets back to you as soon as possible.
Please follow this path to register your concern in Samsung Members Application (Open Samsung Members Application > Get help > Send Feedback > Error report/Ask questions).
Note. please attach the error log file within 15 minutes of the error occurred.
If you use truecaller uninstall and reinstall truecaller. Worked for me. It messes up phone missed call notification somehow even if not set default. When reinstalling do not allow or enable the setting named as show name and photos for missed calls in truecaller because only one app is allowed to show missed call notification and truecaller will not show if phone is offline or battery is optimised
