Category Posts Not Collapsing

Trying to get my posts in my various categories to stay collapsed. I’m using the minimalist theme on my website, and as you can see my latests posts are collapsed. However, when you go to Work and select a category, they all show up at once on the page – bit messy really. I’m certain there is a way to change this, just not sure how to?

Did a bit of searching and found out that it’s got something to do with the javascript used for the functionality of the site as pointed out in this topic.

Does anybody know how to get this functionality working for the categories? You’d be an absolute lifesaver if you do as this problem is stopping me from making some essential layout changes to my site.