Hello Tlfmd,
The following steps may be able to help you receive calls on your iPhone:
"Contact your carrier
When you contact your carrier, make sure that:
• Your account is set up to use your iPhone.
• There aren't any localized service outages.
• Your account doesn't have a billing-related block.
• Your calls don't have errors on the carrier system.
Update your software
- Check for a carrier settings update.
- Check for an iOS software update. Some updates might require a Wi-Fi connection.
Check your iPhone settings
- Turn Airplane Mode on and off. Go to Settings and turn on Airplane Mode, wait five seconds, then turn it off.
- Check Do Not Disturb. Go to Settings > Focus > Do Not Disturb and make sure it's off.
- Check for any blocked phone numbers. Go to Settings > Phone > Blocked Contacts.
- See if Call Forwarding is turned on. Go to Settings > Phone > Call Forwarding and make sure it's off.
- Check to see if Silence Unknown Callers is turned on. If the setting is on, a caller must be listed in your Contacts or Recents. Or they must have shared their number in Mail or sent you a message using that number in order for their call to go through. Add their number to Contacts to ensure the phone rings. Calls from some third-party apps might not go through.
Check your network settings
- Reset your network settings. Go to Settings > General > Transfer or Reset iPhone > Reset > Reset Network Settings. This will erase all current saved settings, including Wi-Fi passwords, preferred networks, and VPN settings.
- Try to make or receive calls in another location."
More details here: If you can't make or receive calls on your iPhone
Best regards.