When a user creates a site with a secondary site URL they should not be able to create another site that has the same secondary site URL. This was not possible in earlier versions of AM somehow this has been introduced.
- Create a site in AM add a Primary Site URL and a Secondary Site URL and save
- Create another site in AM add a Primary Site URL that does not Match the Primary or Secondary Site that has already been configured.
- Add a Secondary Site URL to this new site and ensure it matches the Secondary Site URL of this first site and save.