Internet drops completely many times each day

[LGratz]

I teach for a university via the Zoom platform and it is becoming nearly impossible and certainly frustrating as the ComCast/Xfinity signal drops out completely many times a day. For the last class today, I resorted to my iPhone hotspot. I have done all the usual things. Can someone help me understand why this is happening and how to fix it short of changing providers?

[EG]

For a test, does a computer / device hardwired directly to the router / gateway device with an ethernet cable have the same problem ?

With this test, we are trying to isolate this from being either a WiFi-only problem or a problem with the general connection to the Comcast system which would of course affect both. It's a good first step of troubleshooting before we proceed any further.