PoHq:
Trying to test mine at the moment. Latest iPhone iOS 15. All enabled in options, I turn on airplane mode and enable wifi, I see Voda NZ Wifi but when I try and make a call it says no network available turn off airplane mode.
Airplane mode + VoWiFi seems to work (tested to voicemail) on Android. Maybe an iOS implementation? Have you made a VoWiFi call while airplane mode is off (just wondering if there's some 'activation' involved)?