Internet Instability when using video conferencing, Teams & Zoom

For several weeks I have been experiencing internet instability on online conference platforms, every time I’m on a call, using or not my video camera, the call will drop for a few seconds and then continue.  I have 2 gig speed modem and I'm getting over 500Mbps down and 160 mbps up at the office computer.  I live in a two bed apartment, which is small. 
A Xfinity tech came two months ago and changed our modem, but we still have the same issue. Every time I call the support team says that everything is well on their end but it’s extremely frustrating that I’m on a 30 min Teams call and the call drops like 5 or 6 times for 10 to 20 seconds at a time.

Can anyone help? Thanks.