I just got an S4 and suddenly I can't use wifi calling at my house. I used it on my old phone (mytouch 4G) all the time without issues - same router, Internet still works at the house, the phone will even connect to the wifi, it just won't connect to wifi calling. It does, however, connect to the wifi calling at my office and works perfectly. They did replace my sim card when I got the S4. I have no cell service at my house so wifi calling is pretty much essential. I have tried disconnecting and reconnecting to wifi, removing the battery, rebooting the router...can't get it to work. Any suggestions? Also please note that I'm super dense when it comes to technology, so please dumb your answers down as much as possible Thanks in advance!