Picture Slider not Working

I have a picture slider on my homepage (www.matjhabengpublity.co.za) and up until about 2 weeks ago it worked perfectly. I would be able to select six posts as “primary” and their featured images would appear on the slider. For the past weeks my selected six appear, but the images were static and not “inside” the slider.

If anybody has any tips or ideas as to why this is, I’d love to hear them. Thanks!

The website I need help with is matjhabengpublicity.co.za