Automatic redirection of "Additional Domain" to HTTPS version

I have the latest version of OS X Server (5.0.15) installed on a Mac Mini with the latest version of Mac OS X El Capitan (10.11.3).

I just discovered a bug I've never seen before in the Websites service.

Imagine I have to configure a new Website with a domain name such as "www.abc.com" and I decide to add "abc.com" and "www.abc.us" and "abc.us" in the list of Additional Domains, the goal being that whatever domain name the user choose, it will invoke the same Website.

So far it always worked that way, but now, whenever I go to any of the Additional Domains, the server redirects me to "https://abc.com" that eventually display the default secure Website of the server, because I do not have an SSL configuration for that domain. That is pretty annoying.

Now, I had other Websites configured like that before and they still work.

The difference between the old ones and the new Website I have just configured is that for the latter, I decided NOT to use the default directory (in /Library/Server/Web/Data/Sites/) to install the Website and I created a custom directory, something like "/websites/www.abc.com".

That is the only difference. I have no other issues (DNS, directory permissions, etc) I'm sure.

Did anyone else experienced the same problem?