No, there are no filters in that way. Maybe they are posting in relays the app doesn't have access to?
nostr:npub1gcxzte5zlkncx26j68ez60fzkvtkm9e0vrwdcvsjakxf9mu9qewqlfnj5z Is #Amethyst moderating a user's own follows? There are pubkeys I'm following that never show up in my feed even though I know they're posting.
Discussion
Hmm, it's the same relays only viewed from within Plebstr. It's possible my custom relay settings in Amethyst are causing it, I'll try playing around with these