EDIT: I just realized that I probably just accidentally manually disabled it somehow? My default languages were Undetermined and Cymraeg (Welsh) for some reason. I do not speak Welsh, fortunately. I don't know how I would've achieved that but it's probably not because of the instance, now that I think about it.

~~In my opinion, they should have English as a default language. I don't like being Anglo-centric and all but like, most people using Lemmy definitely speak English and most people probably don't know that this setting is causing communities to be excluded in the first place.~~

Really I think every language should be enabled by default. Like make "unspecified" language include other languages. Or have a "see communities using any languages" option. I don't know if Lemmy can do that though. Content shouldn't be hidden by default methinks, at least without informing you of it explictly. And this is just a Boost thing, but I can't see the option in my account settings in-app.