What error do you receive, can you describe what “stopped working” means?
um, hows that? I don’t think that is the case, unless you have a firewall rule that is blocking your access to that url; I don’t see any such rules in your account) 
I see a 522 on the site, is that the error you’re getting? Can you share the url you are trying to access? You may want to contact your hosting provider to check if they are seeing error in their logs.