I have T-mobile magenta max, great internet connectivity, even with WiFi calling off still I have issues with robotic calls. It just takes one app r web page being open before a call comes on, and here we go again! Voice comes in distorted an robotic. I called T mobile and was on the line for one hour, the rep couldn't grasp the issue after putting me on hold for 5 times and asking questions after questions. I gave up and now I use my phone for work the way I used to use a dumb phone from 2004. In fact a 1400 dollars phone works as a 50 dollars Nokia with Symbian OS.