Thanks for the quick response. Do you have any other theories because in my project I've declared a theme in my root component (App.js) and the Loader is working in other sub-components, just not in this scenario. As a test, I imported the style again in the component I want to use the loader in, and its still not visible.
Also, why is a theme no needed in the Loader demo? its not specified when in the source or the StackBlitz demo?