Hello All, I just switched from ATT to T Mobile and kept my iPhone 6+. I had ATT unlock my iPhone last week and got the "congratulations your phone is now unlocked" message in iTunes once i got the go ahead to restore. Everything works as expected, although i don't have an option for switching on WiFi Calling anywhere. I restored, as new, from back up (both) updated, etc....but no luck. Does it mean i need a T Mobile iPhone in order for this to work? Any help is appreciated, thanks!