Hello,
Try to add add-on domain now, It will work for you.
You can access add-on domains temporarily using URL as
http://primarydomain.com/add-on-domain-folder. Once your add-on domains will work perfectly from our server then ask your current host provider to point A record to our server IP. It will reduce DNS propagation time. Once it resolve properly then point name servers of our server on your domains from domain registrar end.
Regards,
Vasco S