I found the problem with my site – it was the mailchimp code on a widget that’s messing things up. Try removing it and see if it fixes your problem as well.
I now use a Mailchimp plugin instead and it works fine.
I am seeing the same problem with this site http://gmat.wpengine.com/ – search button doesn’t work and menu button doesn’t work on mobile. I tried disabling all plugins and also re-installed the theme but same issue… ?
