​@leromancer  After reading through this thread I'm surprised no one has mentioned your phone settings.

Here’s two thing's to do 

1) login to you IDMobile account via app or web and turn off Voicemail. This should be in Manage ID Services.

2) go into your phone and do this turn off Voicemail, I'm aware you may need you voicemail at time's but if this fixes your call's being received then the lack of voicemail is not an issue then.

To stop calls from going to voicemail, first check if Do Not Disturb or another Focus mode is enabled by swiping down from the top-right and disabling it. If that doesn't work, go to Settings > Phone and disable Silence Unknown Callers and Call Forwarding. 

1. Check and disable Focus modes

From Control Center: Swipe down from the top-right corner to open Control Center. Make sure the moon icon (Do Not Disturb) or any other Focus icon is not highlighted. Tap it to turn it off if it is. 

From Settings: Go to Settings > Focus. Tap on Do Not Disturb (or any other active Focus mode) and ensure it is turned off, as this site recommends. 

2. Check Phone settings

Go to Settings > Phone. 

Turn off Silence Unknown Callers if it is enabled. This feature sends calls from numbers not in your contacts directly to voicemail. 

Check Call Forwarding. Make sure this is turned off, according to this YouTube video. 

3. Other potential solutions

Restart your iPhone: A simple restart can resolve many issues. 

Toggle Airplane Mode: Go to Settings or Control Center, turn on Airplane Mode, wait five seconds, and then turn it off again. 

Check for blocked numbers: Go to Settings > Phone > Blocked Contacts to see if the caller has been accidentally blocked. 

Update iOS and carrier settings: Go to Settings > General > Software Update and Settings > General > About to check for and install any available updates you want to install.

Joe 😉