It seems like everything is back up again.
I've done some DNS stuff and now it magically works again.

The hosting provider, Venocix, has responded and they have forwarded the issue to someone in charge of the server (I assume).
I'm sorry for the issues but there is nothing I can do.

Someone is trying to brute force their way into the server while it's having network issues. Could be a DDoS attack on the server...
I don't know if those two things are related, but there is nothing I can do at the moment but watch.
I will go to bed now and hopefully, it's resolved tomorrow.

Restarting didn't help. The bot is back up again but the client's API is still not accessible.
Therefore the homepage loads for a very long time and the login will not work.
I can't really do anything because this seems to be a network issue, which I'm not in charge of.

Restarting the server to hopefully resolve the issues

The bot is still responsive, but the API, including the login, is down. I'm looking into it.
This also affects the homepage, specifically stats.