When will VoLTE and VoWifi be available? ( calling via 4G or Wifi )
Both VoLTE and VoWiFi are SIM and network dependant. The WiFi calling option is available in the network menus but wont do anything unless your SIM has been provisioned and the VoLTE option doesn't even appear until the SIM is provisioned.
It looks like this service is strictly the mobile phone operator when you update your phone. It does not depend on the SIM card.
You can update your phone until you are blue in the face but it wont work until the network provisions the SIM card.
MrBelter . I have a sim card which is functioning VoLTE and VoWIFI in an SE iphone. Maybe it would work in Nokia 8 if I had the option in the menu.