Unstable Internet (wifi and ethernet)

Internet connection is unstable. The xfinity app and sites run their tests and say it all works but I can't be in an online call, or stream a show, or what have you without repeated internet drops. Sometimes the connection is wholly unusable and I have to write off using wifi for the day. All while xfinity app says my connection is Perfect! Resetting gateway, unplugging router, restarting devices, nothing changes the problem. This is both on my desktop, with an ethernet connection, and in wireless devices. Some devices rarely work when connected (though that could be a device issue).

I'm aware there's been some work and service outages at my location, but this is a problem all hours of the day when no work is being done, and has been a problem since I first moved here and got Xfinity. I was content to pay as much as the bill is because of the need for internet of good speeds, but at this point I could be paying for the cheapest plans and get equivalent speed. Or I could just switch to a new service provider at this rate.

And to add frustration, your support solutions are useless. Xfinity assistant sent the same article links I've read and done, and searching this site gives a USER FORUM instead of an email or phone number.

I'm hoping it's something simple, like I just need a new router. Because I would prefer to have the service I'm paying for then need to figure replacing it.