That may be carrier specific and some carriers, like Verizon, disable user control of those settings if you have a carrier locked phone. I don't know whether it's supported on your phone or not (the phone could support it, but the carrier may not). Both the carrier and the phone have to support the feature. I suggest calling your carrier first, since they control the wi-fi calling, as well as the LTE calling. You might see (carrier name) wi-fi calling when wi-fi calling is active.
HD voice is working with wifi calling for the same carrier in other devices, regardless of the carrier, hd voice us not working in Samsung for wifi calling.
Well, maybe your carrier did not enable it for your plan/phone. Wi-Fi Calling, and anything related to it, is controlled by your carrier. This would include VoWiFi and HD voice. Don't understand why you would need HD voice anyway, on any type of call other than that it's a feature and you want to use it.
