Yes, I have HD voice turned on and I have the WiFi calling on as well. For some reason the WiFi calling isn't working. I have poor service around my house (inside and outside). I have the Samsung Galaxy S7.
Do you ever get in wifi calling mode? Try turning off cellular radio and then connect only to wifi, do you get the VZW Wi-Fi indicator and does calling work?
You can also try turning off HD voice to force the phone to CDMA 1x mode for calling which still tends to be more reliable.