Beehaw.org defederated from lemmy.world, and sh.itjust.works, effectively disconnecting from them. According to the post they made, they were disconnecting due to the influx of new users on both those instances overwhelming the moderation tools and moderation team that they had going.

It's worth noting that Beehaw describes itself as a safe-space instance, where registration is restricted, and all users registering have to be approved by instance operators. This is fine and all, but there's an issue. See, with the way that Lemmy and Federation works, you don't have to be a registered user on an instance to post there. So a user can just circumvent Beehaw's account creation restrictions by creating an account on a less-restrictive instance (such as lemmy.world), and posting over there. Which isn't ideal for Beehaw's moderators and operators, who had trouble dealing with "bad actors" from those instances (trolls and things), simply because their open registration policy meant that there would be be an influx of new users who found Beehaw's community through lemmy.world, or sh.itjust.works, or trolls who could comment on Beehaw's posts through them, circumventing bans and things.

Since it was too much for them to deal with, using the current tools that they had available to them, Beehaw defederated themselves from those two instances, effectively separating themselves from those two. Beehaw users won't see new posts from those instances, and those users wouldn't be able to see any new posts from Beehaw.

Given the current state of things, I wouldn't be surprised if Kbin might also be on the chopping block, since they've been having a few problems with users from there too, but that's neither here nor there.

Still, the Beehaw operators have said that they're willing to reconnect with those instances once Lemmy develops better moderation tools that let them manage that amount of users (and they're in contact with the operators for those two instances), but we have no real idea when that might be.