FaceTime disconnects on Macbook Pro after half hour

I have a recurring problem with receiving FaceTime calls on my MacBook Pro using Ethernet. An incoming call appears on both my iPhone XS Max and MBP. I choose to answer on the MBP. The call is successful for half an hour, then fails due to a claim of poor bandwidth. Hard to believe with xfinity 300 Mbps which regularly measures at 350+ with SpeedTest. We resume the call on my iPhone, over wifi on the same network. No one else in the house has any problems with the internet. The most frustrating part is that after the FaceTime disconnect, the internet connection on the MBP is trashed and will not reconnect without a total Restart. Catalina 10.15.7, FaceTime 5.0