[doublepost=1491072987][/doublepost]I have recently switched to Tmobile and chose the iPhone 7 plus. I have been having the same issues. I can be talking to someone on the phone then my phone cuts out, sometimes i can still hear them but they cant hear me. Other times my phone goes completely quite, then after a few minutes i can hear other person again. My husband chose an LG phone and has had zero issues. I'm switching my phone out today. Also, my niece has the IPhone 7 with Verizon and loves her phone, she has no issues with her service or phone.
Your phone has a intel modem that may be what the issue is the Verizon one dos not used intel modem so your niece is not having the same issues