Hi, we'd request you follow the below steps:
1. Clear system cache.
2. Try the same under safe mode:
Hold the power button for 5 seconds => When the screen flashes with option => Press & hold power option => You will get an option to restart in safe mode
3 . Swap the SIM into other port and with other phone and see if the issue is with SIM.
4 . If still you face the issue
factory reset your phone after taking a full backup :
https://www.asus.com/support/FAQ/1006346/5 . If it doesn't work check with Network provider for any network related issue.
6 . Last option would be to visit the service center to have a
check. Locate here:
https://www.asus.com/in/support/Service-Center/India
