The infinitely rotating button happens if their email settings are invalid- just discovered that on my instance. I have mine set to open but require email validation and everything seems to happen instantly, but if they require admin verification it may be bugging out and not telling you.

Hopefully many of these wind up staying private longer, 2 days isn’t going to convince reddit admins of anything. The real shift will come when large subreddits start actively pushing their users to Lemmy or Mastodon or wherever else, nothing happens till users leave en masse.

I think you’d need to get in contact with the instance admins, ownership can be transferred to users on a different server, but only by a current mod. If the community is inactive it might be easier to just make a new one.