Unable to create a top level server

I have had no issues before but now when I click on create virtual server it automatically defaults to alias of xxx.com
I don’t want it as an alias but don’t see an option of adding another server. I currently have 10 top level servers … is their a limit? I am logged in as root.

I deleted 1 of the top level servers and now the option to add a new top level server appeared. So my question is now how do I remove that limitation?