We would suggest you to follow the mentioned steps to resolve the issue:
>Check via other SIM card in the device.
>Perform Interactive checks through Samsung Members app (Samsung Member > Get Help > Interactive checks > SIM Slot).
> Open Setting > General management > Reset > Reset setting > Reset setting.
If still issue persists then we would suggest you to contact your SIM provider.
For further assistance, register your concern in Samsung members application (Open Samsung members app >> click on “+“icon > send feedback >> error report / ask question).
