For a test, do devices that are 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, see ? It's a good first step of troubleshooting before we proceed any further.
I just searched around since i have encountered this issue since upgrading to the GB internet about 3 weeks ago. It happens on both wired and wireless devices. I have disabled the hot spot ( though looking at the wifi analizer it doesnt look to be disabled) I have moved the 5 and 2.4 ghz channels to the best channels. Its most noticable on zoom calls and online gaming. i have the advanced Wifi 6 gateway. i have also ensure all my cable connections are nice and tight as well. its really annoying.