Hiding the sub-nav on Section 4

As title itself, I need to hide the sub-nav on Section 4 (where I’ve activated the Google Map) because 1)it doesn’t show properly 2)the only you can see looks ugly af.

I’m trying to customize CSS to hide it but it never works. I can just hide it in all sections or none, but not only in #4.

Any help/suggestions, please?

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