Calls keep dropping, whether receiving or making
I bought a brand new iPhone 11 Pro in December 2019 and every few weeks calls keep dropping, when I make or receive them. I even had my phone diagnosed and had a new SIM card but every couple of weeks, calls keep dropping. Once I restart the phone it seems to start allowing me to make and receive calls. I read online that it is a software issue? I have an appointment with Apple to inspect my phone.
iPhone 11 Pro, iOS 13