Menu drop-down list problem

I’m having trouble getting the drop-down on the menu to function properly. I have 2 sub-items right now under the “Our Services” tab but when you hover over it they do not drop down. An empty drop down bar appears that’s much too wide and with no content in it.

The website is https://www.huntingtonpropertymanagement.com

I am using a theme called diamond.

Thanks!