Why does it say "pending" when I try to join a community outside of my local Lemmy instance?

It's a bug IIRC. It might be fixed in one of the upcoming upgrades: https://github.com/LemmyNet/lemmy-ui/issues/1315

https://github.com/LemmyNet/lemmy/issues/3203

Thanks for letting me know. Really appreciate it!
- Also from I personally experienced and what others said too, it seems to be purely visual and those communities still show up in your subscribed feed as if it went through normally.

It's not a bug. You're trying to subscribe to a Beehaw community.

What happened is that Beehaw has de-federated Lemmy.world. They've essentially banned, from their instance, all users on the lemmy.world instance. This was due to a combination of Beehaw having very heavily moderated communities and the influx of new users onto your (and my) instance.

Some of the new users were trolling the Beehaw communities (including user posting a picture of their penis in a Feminist community) and couldn't be banned because they could just re-create an account on these two instances as they were running with open sign-ups (Beehaw requires manual approval of user sign-ups).

Because of these things Beehaw's moderation team de-federated lemmy.world and sh.itjust.works until they could work with the two instance owners to come up with a solution. As of last update, they had reached out to lemmy.world and sh.itjust.works' admin staff but had only heard from sh.itjust.works. They said they're confident in re-federating at some point but have not provided a timeline.

Until then you will not be able to access Beehaw communities or see any posts from Beehaw users until the de-federation has been lifted.

I've got some "pending"s on kbin.social communities, which I don't think is defererated? Is that a bug or do some communities just set up that way?
- That's the bug others have mentioned.
  
  Sometimes it's the remote service timing out, sometimes it's the local service. Sometimes it silently fails, other times it silently succeeds but still says it failed, and many times it succeeds and does the 'Joined' thing.
  
  This is all a work in progress. Give it time.
Ah, so I'll delete all my requests from there. If I wanted nazi controlled boards I would have stayed on Reddit.
- Man, people are really over using Nazi. At this point it's basically become: 'things I don't like'.
  
  Beehaw is, if anything, very left and was trying to get rid of trolls that they couldn't ban because the troll would just make a new account in 5 seconds on one of our instances. I'm not at all a fan of de-federation, see our community discussions, but I understand the problem they were trying to avoid.
  
  It seems like a pretty defensible position to not want random trolls posting pictures of their penis on random communities. They were unable to resolve the problem with the moderator tools that they had so they were forced to de-federate. Not exactly the Third Reich.

Thanks for this. I’d wondered if there was some kind of verification going on.

That community is on another instance that currently isn't allowing participation from lemmy.world users. There's a PC Gaming community on lemmy.world. I don't know about a general video games community. Someone should start one, because who knows when, or if, that other instance will open back up to lemmy.world users.