wifi calling dropouts

Frequently during WiFi calling the party we are talking with can no longer hear us. We can hear them however. Sometimes after 20 seconds or so they can hear us again other times they never can hear us again and we need to call them back or they call us back. The call back does not always rectify the situation. We then have to remove wifi calling from the phone and make the call over cell coverage. Our cell coverage is xfinity mobil. We have week xfinity mobil coverage inside the home so wifi calling is essential to our business. Our internet response while doing business also occasionally has an extended response delay and after a period of time will reengage. We have cycled power to the modem numerous times in an attempt to rectify.