I got it! I watched Ben’s video again and realized that I hadn’t placed the related items component inside the corresponding CMS item that provides the data for processing.
Now everything is working. BUT I noticed one thing: when I set the limit to 3 in the related items settings, only 2 are displayed. If I set the limit to 4, only 3 show up, and so on…
Not a big deal overall — just a small cosmetic issue.
