CMS - Filter List Grid

I am new to Webflow. Our site was built by someone else but they are no longer offering much assistance. Since I have added entries to the CMS it does not seem to be working very well with the filter list grid display we are using to display the information.
We have 3 CMS lists working together here:

  1. Main Categories
  2. Secondary Categories
  3. Works

We have a works page on the website and when we select a category and Secondary Category it should filter the projects to show us all that match those categories - I can confirm that there are many projects that match the categories but none are showing on the site.
The section says it is inheriting 2 selectors but I’m not sure how to tell what those are or what could be going wrong.

Any help would be much appreciated!

Here is my public share link: LINK
(how to access public share link)