This is not the first time this has happened, so it is probably temporary.
Also, the .onion of the site still works.
Remember that to access the .onion you need to first decode the text I send (without the Lemmy URL) with a tool like Base64 and use the Tor browser.
Edit: They also have a Mastodon account where they keep actively informing about the situation of the site, just 11 hours ago they said they have a problem that they cannot solve.