Intermittent wifi 2 months

I’ve had intermittent wifi issues going on 2 months. I noticed this happened after an outage in my area.

I’ve gone through 3 technicians, 5 supervisors, 50+ phone/chat agents, and no one can give me an answer. The current supervisor I talked to actually turned out to be a friend of mine’s neighbor and has scheduled to come out personally (I hope) to check out my setup.

I’ve had 2 of the 3 techs change fittings and use 2 separate voltmeters to check my line connection in my house. The lines are good, and actually Comcast installed these 2 years ago (though the 3rd tech claims my lines are bad and Comcast doesn’t install these lines, even though they were indeed installed and was charged for it). I even hired an electrician to check my lines and he confirms there are no issues with it.

I had my modem changed out 4 times with Comcast, one being the older black model, and then the others the grey xFi modem. I currently bought a motorolla modem/router combo to test if it’s a Comcast modem issue and to control my broadcasting channels, but still no fix.

I have made small progress with disabling the 2.4 GHz frequency. My phone, laptop, and WiFi tv box no longer experience issues that I notice, but I have a few home devices that need that frequency, and my main cable tv box still freezes and loses sound when I use streaming apps such as Amazon Prime.

Can anyone give me any advice to troubleshoot this further? I’m going on a loop with Comcast with absolutely no help at this point- though having this supervisor appt might be hopeful but I’ve lost trust in the system at this point and I have to work from home starting in August.