My impression is that libertarian communities, similarly to Mensa, have more hostility between members than you might want to see in a well-functioning community. There are libertarian communities, but they are less community-like than the term would lead you to expect.

That might be directly related to the kind of person who joins a libertarian community (as seems to be the case with Mensa), or it might be an artifact of the fact that women hate libertarianism.

There is and it's extremely cultish.

There's definitely libertarian communities. Although I'm sure they can become cultish, I imagine they are much less likely to become cultish than the state, since libertarian ideals would mean those communities produce more liberal ideas and thus less group think.

I wouldn't expect the Libertarian Party to become fascist but crazier things have happened.