'Enter a name and password for network "Xfinity"' popup

Starting two weeks ago (in my fourth month of service, I continually get a popup that declares : Enter a name and password for network "XFINITY"

It doesn't accept my account name or password. It doesn't  effect my service, though it is anoying as it is constantly there.

Why is this? What does this want? It doesn't accept my account name or password, as I have said. Pop up that won't go away