The community does not show up in search, and when I enter the full link (!community@ instance.com) , it seems to treat it as a string to search for rather than an address.
I don't know actually. Other apps have also had trouble with finding communities that aren't already federated with your instance, I've had to do it via browser before. Would be great to have it all in the app.
Strangely, this might be a bug. The community is on kbin.social, which my home instance is definitely federated with. Searching through the history of my kbin account from lemmy shows no posts or comments to that one specific community (!WanderingInn @kbin.social). @ljdawson, any clue about this?
While your initial question still applies (I tried searching other obscure remote communities on Sync and couldn't find them) I think in the particular case you brought up there is some federation issue between lemmy.world and Kbin.social. Might be related to the DDOS attacks on .world recently, who knows (there's been federation issues before).
I tried finding it on my lemmy.world account and didn't, but it shows up fine when searching on feddit.nu. So that seems to be a lemmy.world-issue rather than a Sync-issue.
I just assumed that was where your Lemmy account was that you used to search. Did you search from Sync without being logged in? It wouldn't surprise me if lemmy.world is the default instance, since that's where ljdawson is registered.