OnePlus 9 Pro Calls Problem

My wife and I upgraded our LG G7 thinQ phones to the OnePlus 9 5G using TMobile.com website. Both of our new phones have had this same issue randomly since we got them on April 14, 2021. Sometimes they can hear us but we can't hear them or we can hear them but they can't hear us. Also sometimes we will reboot the phone and see there are voice mails we didn't even know they tried to call because it never rang. And sometimes the text messages won't go through until we reboot the phone. We are missing work calls, personal calls, and I would hate to have to call 911 and have to reboot the phone multiple times while bad things are happening.