34 disconnects within 24 hours, phone support won't help!

I've been suffering with poor service from Xfinity for over a year now and no one helps.

My Internet literally disconnects dozens of times a day, every single day. I call and of course by the time someone answers it works as it disconnects for 30 seconds to 7 minutes each time before randomly working again.

One time around a year ago they sent someone who said maybe it's the T Splitter and provided a new one. That did nothing.

We've been dealing with the kids getting kicked off online classes many times a day and it's just ridiculous. Even when Xfinity called after the initial 'we have to reset your device' set the call dropped because the wifi disconnected!

I am 100% certain this is not my modem or router. They were less than 2 years old, and within the last 2  1/2 months I bought brand new ones again and it's the exact same problem. 

It basically has to be the coax cable coming into the house from the xfinity box outside, yet because of Covid the phone support says they won't send anyone out since it intermittently works!

The Xfinity app pretty much always shows the modem is offline even though it is online the majority of the time (except about 1-4 hours a day during the 30+ disconnects for 30 seconds to 7 minutes each).

This disconnecting happens day or night, I found a program to track it so it should have nothing to do with maybe there's too many devices on at the time etc. I also bought the most expensive equiptment I could find at best buy that says it works for a 7,500 sq ft house (which I don't hvae) so I honestly can't think of anything other than it having to be on Xfinity's side.

I've replaced every single coax cable on the inside, as well as the TSplitter, as well as not even using the TSplitter and therefore not having access to the TV I pay for. I've also unplugged the devices hundreds of times and also tried to add them again to Xfinity to confirm that MAC address was entered correctly. Nothing works on my side.