Recurring problem

We have repeatedly had our TV’s stop recognizing that we have a Xfinity Internet, which causes them to stop launching all Apps. We have spent many hours on the phone and had techs to the house, but a few weeks later it happens again I have unplugged the cable box and restarted the router and plugged the box back in as instructed, but it does not fix it. We have been loyal Comcast/Xfinity customers for decades, but now we are fed up. It is so hard to get to a person who can look at the account history and fix the problem.