New service and pc ethernet connection is being blocked randomly anywhere from 15 minutes to 12 hours

I recently switched from my local dsl service provider to xfinity for a better price and higher speeds.  I got everything setup and am having a problem with my hard wired ethernet connection to my pc which has worked flawlessly for years on my other service.  My wifi connections and my ethernet connection to a xfinity flex are not affected and work fine even when the pc is blocked.  For some reason going anywhere from 15 minutes to 15 hours my pc will lose its internet connection with the error of an invalid IP address reported back by windows.  My Pc doesnt have wifi so I cant try that. The only way the connection can be restored is a full computer restart.  It will not connect or communicate with the modem at all once triggered unless restarted.  Ive have called tech support a few times now, I am using the recommended settings from xfinity website for windows 10 firewall, I have replaced the cable with a new one, tried different ports and xfinity sent me out another router/gateway and its still is doing the same thing.  The only thing I can think of is I am somehow triggering some kind of security that xfinity has set up and its blocking me, but it seems to be completely random when it happens, some times it will do it 3 times in an hour and others it will make it most of the day.  Really hoping someone has delt with this before because Im lost at this point and I can normally figure out most computer problems.