@vinesnfluff Honestly, probably some sort of hiccup between the instances. I see about 19 magazines on pawb.social from kbin.social, and that seems like maybe half of them when I actually go over there. Doesn't include the mlp one, either.
They are theoretically compatible, but early days on both, and all the instances have far more people then they were ready for. I wouldn't be totally surprised if they were both just backed up...