Your wikis is on MediaWiki 1.33, while this wiki is on 1.37. The HTML structure and classes have changed since them. You may want to have a look at older versions of the script here using the page history.
How is the "hoverIntent" plugin built, please? Otherwise, this is what prevents the script from working. I tried to load them with mw.loader.load() and mw.loader.getScrirt(), but alas.
