No/yes. The link is to http, the server does not redirect to https. So it works. When manually adding the "s" (or using a browser that tries to upgrade on its

No/yes. The link is to http, the server does not redirect to https. So it works. When manually adding the "s" (or using a browser that tries to upgrade on its own), then yes, certificate error. Not only that, ignoring it the server responds with an error. Simply use a browser that does not try to enforce https.