I'm using the University of York version of CMoS, classic footnote style. One citation, to a book chapter in an edited collection, insists on generating in the "short title" format instead of giving the complete publication information, even though another work in the same note and cited chapters in other notes all generate correctly. I've tried deleting the whole footnote and re-creating it, but no luck. Even more oddly, if I create the note in a different document with York CMoS, it generates correctly. I don't see anything that might be interfering.