This has happened several times to me, so I thought it was time say something. I delete a product but it remain as a “ghost” in the collection. I say “ghost” because it looks as though it is real but when you click on it, it takes you to the “oop’s” page. Here is a link to a collection and the very last product is the example happening now. I have had more and I haven’t documented them, so this is the only one that I can send you: https://www.zazzle.com/collections/golf_club_golf_league-119684014077859963
Thanks.
Vivian