Disconnecting From Applications But Not Losing Internet

Hello,

I recenelty moved and transfered my xfinity service along with me. Ever since I installed the modem in my new apartment i've had an issue of frequent discconnects (sometimes instant - ~5m) from all online applications (pc games, spotify desktop app, microsotft office apps, etc), however when this happens I do not lose internet alltogether, as I have continued to stream video and check my web based email while the dissconencts occour.

I have power cycled  and factory reset the modem multiple times to no avail, i've turned off my firewall, and tried many other "fixes" but it seems no one has expierenced the same issue. I even went as far as getting a brand new modem from Xfinity with the same results. 

Furthermore when attempting to acces the gateway through the browser I enter a gateway that is not mine, it shows an SSID and password that are not the one on my gateway and conencted devices that are not mine. It's almost as if there is another existing connection at this location that is constantly kicking me off.

The overseas support team I've spoken to says everything is fine and there is nothing they can do which is extremely frustrating as I had zero issues before transfering service.

Any assistance would be much apprecaited.