mobile navigation issues with Zerif Lite Theme

I’m having some troubles with the mobile navigation of my website.

http://98d.e80.myftpupload.com/ ( The site isn’t done yet, so I haven’t linked the URL yet).

When I click on the Services page on mobile and then try to click on the navigation menu again it glitches out.

I do have custom css, but it’s not happening with any of the other pages.

I am new to wordpress, so any help is greatly appreciated.

Thank you in advance!