Slide In Plugin not working for Mailchimp Sign Up

I've installed the Slide In plugin to use as a Mailchimp signup form. The slide in works as it should however when I tested it by entering my email address and then hitting submit, nothing happens. The slider doe not go away and no confirmation. Any ideas? It's for I've got the slider in draft mode for now until I can get it fixed so let me know when you want me to enable it for testing. Thank you!