A:AnswerI worked with technical support from T-Mobile and Sony yesterday with a conclusion that only mobile phones that are T-Mobiles branded, i.e. have specific T-Mobile SW will enable the WiFi calling option on the phone, hence no work around and leading to me returning my Sony XA2 to Best Buy
A:AnswerYes, its a North American version, GSM phone and Unlocked. So its compatatable with AT&T and T-Mobile networks as well as any of the MVNO's that use their networks.