The below paragraph was posted by a "gold problem solver". I followed his directions and was able to view my channel lineup. I went through every channel on the TV and I am getting the channels exactly as listed.
Something positive for a change.
When you log in to https://customer.xfinity.com/#/services/tv (My Account, Services, Manage TV) and click "View your channel lineup" under Common Solutions, the resulting lineup page should have a Print link in the upper right corner that produces a PDF copy of your channels.