Gregory's Server
I've found a lot of flakiness in activity pub comment threads between PeerTube and Mastodon alone, with each federated instance having random seeming replies and sub threads missing. Past behaviour may make malice an easy assumption, but for something like this with new software, bugginess or misguided implementation is much more likely.
@errhead @dansup @pixelfed Even if that's the case with Threads, according to Meta's CV it's something hard to believe. Or, in other words, "The boy who cried wolf" story.