I have iPhone 7 and iPhone 6. Both used to be able to support wi-fi calling at my house. Few weeks ago both stopped working. Tried every single option I read about and no luck. The recent changes in my home were moving from TimeWarner wifi to Spectrum (which is the same company, same router, etc.), added a new Airport Extreme as extender. For a very short period of time I used a new cable modem but then disconnected and went back to the old one (which the wi-fi calling used to work with). In addition, even when outside of home, trying with other networks does not work for me anymore. Any suggestions?