Intermittent Wi-Fi

For over a week now we have been losing WiFi connection. Two of us working from home, one schooling from home. Every morning we had to restart our modem. We own our own modem and separate router. Both Netgear. My son keeps getting kicked out of his virtual classroom. It got so bad we were resetting the router several times a day. Couldn’t even watch Netflix. We spent hours on the phone with Xfinity. Bought a BRAND NEW modem and router, and still having these connection issues! Netgear says it’s a modem firmware issue (not router) and Xfinity needs to push the update through. Xfinity says they don’t do that and everything is correct on their end. In this day of age, I need my son to be able to attend school. I noticed using an Ethernet cable helps with the adult work stations, so trying this for my son Monday. But we lose the WiFi on our phones, tv, Nintendo switch, etc. We upgraded our internet plan with Xfinity to the highest option. Didn’t help. I’m at a complete loss now. We’ve tried everything. Any suggestions?