Never mind. I figured it out. A bit confusing as I wasn't aware of the favorite's "genre" pages. When you enter your first favorite url, you are brought to that's station's genre page (whatever it happens to be), where there is no "Add" button. You must know to tap the little (unlabeled) left arrow at the top of the list to return to the "list of genres" page... where there is an "Add" button. I noticed when entering the second favorite url, I begin, and am left, at the "list of genres" page (where the Add button is). Wish that had happened when entering the first one.