Calls not coming through - possible solution
I had this problem when I first got it.
First under settings->call->Use Internet calling - make sure you select Only for Internet calls.
Now go to wifi and make sure you are connected to a Wi-Fi network - then click the More menu listed under Mobil Network (three dots). If you have wifi calling enabled, go to Wi-Fi Calling Settings->Connection Preferences and select Cellular Preferred - otherwise you won't be able to make calls when not near a Wi-Fi.
Hope this helps
- it took me forever to track it down!