Troubleshooting VoLTE & VoWifi

[yvmuell]

Just a note: VoLTE might only be available when wifi is off…

Did you contact your provider to ask if they can check all settings at their end?

Edit: see this topic

Unknown caller unless volte and vowifi disabled

I dont think that a wifi connection alone will disable VoLTE. Your setting seen the screenshot above suggest you only use wifi calling when no mobile network is not available. I guess you dont see the wifi calling icon in the status bar? Change the wifi calling setting to always use wlan when connected and see if it changes