If he's being told that no channels are in his subscription, it's clear that Something Else Is Going On. Maybe he has a separate account for the internet vs TV? But it's not giving him a login form and immediately telling him he doesn't have any channels, so something's up.
I ran into an issue yesterday where Xfinity (on login) asks you to add a recovery email and/or phone.
It wasn't immediately obvious, but there was a link above that saying something like Other options.
Choosing that lets you create a recovery question and answer. Then it completed the login.
Strange thing is, I already had recovery questions and answers, but it didn't display them.
I see why Xfinity is asking you to update your recovery Q&A's since their data breach may have included that info.
What Information Was Involved? On December 6, 2023, we concluded that the information included
usernames and hashed passwords. For some customers, other information was also included, such as
names, contact information, last four digits of social security numbers, dates of birth and/or secret
questions and answers. However, our data analysis is continuing, and we will provide additional notices as appropriate.
It has to be off on the account that is being used for xfinity internet access
That was it! Like many of my errors seems obvious in retrospect. Many thanks to @chDVRuser and the team at Channels for the outstanding support.
Also @smeiff correctly identified my issue earlier - I just failed to properly interpret: "My actual TV service was linked to another account at the house I'm moving to. I had to sign into where the internet service was linked to and disable the auto-sign in from there!"