Upfront Builder Background Image Slider : Images Not Displaying

I seem to have an issue with a region background slider not displaying the images. In addition, the images no longer appear below the "slide order" in the background settings. This is the second time this has occurred. I deleted the original region and started anew. I was able to upload the images in the new region and now they have disappeared again. I can't seem to point a cause and affect just yet.

Any thoughts?