Hi, it has been that way for a few years. It is not possible to make any outgoing calls when Wifi is on. Instead, the title of a popup "Calling" appears, where there would usually be a selection like "Call via ...." if any voip is configured, and it hangs there. This is independent of - which app is used to call (it seems all dialer apps invoke each other in a loop, sometimes many apps show popups when calling) - which way the call is routed (what app, voip or mobile) - what device (HTC, Samsung) - what Android version (4.x, 6) - what settings any apps have What apps do this blocking? How to find out what apps are involved there? thanks..