Nav-menu items with anchor links for scrolling home page not working from non-home page pages/posts

Site in question is staged HERE.

The home page is navigated via the first three menu items: “Why Jamie?”, “About Jamie” & “Contact Us,” which contain anchor links to their respective sections within that single page. These work fine when a user is on the homepage. However, if a user clicks on “Events” or “Press,” once they are on the “Events” or “Press” pages, the “Why Jamie?”, “About Jamie” & “Contact Us” nav links no longer work; clicking them does nothing.

Thanks in advance to anyone who can help me figure out why.

-Jon

The issue seems to be JavaScript-related, as it works OK with JS disabled.