How do I solve Article Thumb Slider problem?

Hi There,

I want to know that how do I use Articles Thumb Slider to show the different article from the different categories.
The Articles Thumb Slider only show the articles from Sports category and Politics category.
When I selected test category below the selected category, I noticed that the slider on the home page had disappeared. I've created several article under the test category.

I wonder how do I change the picture of the banner.

Please see my screenshow.

Thanks