Virtual server redirects to sub-server

I have a virtual server that is empty, with no feature enabled. It has many sub-servers hosted under it, , , etc…

When I type in the adress in my browser, it redirects to subserver How can I prevent this behavior and just display a “forbidden” page?

I’ve tried putting a .htaccess file with “Deny from all” in my ~/public_html folder but it’s not working.