Login Popup Won't Work Immediately

www.thegroveacademy.com.au - When you click on the 'Parent Corner' menu item which is using gkLogin, the login popup won't show if you click it immediately after loading the page. For it to show up you have to wait at least 3 seconds.
How can I make to login popup show when the menu is clicked IMMEDIATELY after page loading?
Thank you.

This element is driven by javascript which needs to load and it fires only when all dom elements are ready. You site loads quite slowly (probably hosting stuff) and that is main reason of this behave.