broken calls on cell phone

Using tech reset, new T-Mobile iphone 11 Pro with a t-mobile tower visible, strong cell signal and wifi symbols, recipients of my call complain about broken call. I've gone to t-mobile to get strong cell signal but no good. My wife uses iPhone 11 Pro Max, mine is not the max. Her signal and calls are good, always have been clear to recipients. My phone has been reset by tech on line and I have done it a few times  Ive Taken taken phone to Apple Store  for tech investigation and new SIM card. T-Mobile tech did provider system reset.  I can hear well.

fWhat else can I do?