Hey Pcmccarthy1,
We'd recommend reviewing this article as it provides methods in which calls can be blocked or silenced, which may help determine what is causing the issue you're seeing: Detect and block spam phone calls
We'd also suggest checking out this article as it provides steps to help resolve issues with incoming calls: If you can't make or receive calls on your iPhone
"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."
Thanks!