Error: couldnt_find_community

I was browsing all communities on Liftoff, and I came across one that I wanted to subscribe to: [email protected] When I tapped Subscribe, I got an error that the thread[sic] was retrieved from lemmy.world, but I was signed in to lemmy.ml. First of all I don't know why that would be an issue (I've subscribed to other lemmy.world communities before). But I just started using Liftoff so I thought it might have been a bug and I tried to do it from Jerboa. But, [email protected] doesn't show up in the search. Also, I tried in a browser to navigate to https://lemmy.ml/c/[email protected] and I got the error in the title of this post (couldnt_find_community). Navigating to a different lemmy.world community using the same method works fine, but sbubby does not. What's going on?