@kescher activepub doesn't fetch all replies that my instance got to your instance, unless you're following the reply author, or you're following me and I boost the replies.

this is one of several not very intuitive features that people often think of as a bug but it's actually fundamental to keep the fedi as nice as it is (stuff don't get pushed everywhere, unless people in your instance have actively decided to subscribe to them; people you follow have boosted *my toot* into your timeline, not its replies.)