Scroll box not automatically showing up

This works perfectly on my own test site with a Genesis theme, but am having some problems with this on a client’s site. Not sure if it’s a theme issue or a plugin issue (no cacheing plugin installed, so it’s not that). Any help is much appreciated.

The box doesn’t scroll up, instead, a little box floats on the bottom right corner that says “Subscribe!” (no idea where that’s even coming from). When you click it, THEN the scroll box shows up in its entirety…

Also, the shortcode for the 3rd party subscription form does not show up in the scroll box, but rather at the bottom of the page under the footer…Any ideas? I know it’ll be hard to pinpoint this issue on this little amount of information, but mainly just trying to figure out if it’s the theme or a plugin. Thanks in advance.

https://wordpress.org/plugins/dreamgrow-scroll-triggered-box/