Can someone investigate the behavior of VoWiFi? The VoWiFi connection is generally very unstable and is randomly lost, even when the Wi-Fi connection itself is in excellent condition. I suspect this may be a general iOS issue that has been present across several iOS versions. A clear and easy way to reproduce the issue is: Turn off the iPhone screen. Wait 5 minutes. Receive a phone call. The call will not be received over VoWiFi. It will either fall back to the cellular network or be missed entirely. The issue can occur randomly in other situations as well, but putting the iPhone into standby makes the problem particularly easy to reproduce.