Dropdown menu goes up?

First, thanks for making this. It is so much easier than having to add javascript. My question is when I click on the button the dropdown menu appears upward to where the button is the bottom of it and the options appear in a menu above the button. Is this how it’s supposed to work? If not, how can I get it to go down like a normal dropdown menu?

The page I need help with: [log in to see the link]