Hello @com4digital,

When we tested the theme locally, the slider is working absolutely fine.

Also, the slider can be set using pages, post, and category so we are not quite sure from where the first screenshot that you post comes from.

So to make the slider work you need to enable it first by going to Admin Panel > Appearance > Customize > Homepage Section > Slider Section and enable the slider.

Screenshot:

http://prntscr.com/juaukf

Since you can set the slider using Post, page, category, make sure you have uploaded the image in featured image section od individual post, page.

Screenshot:

http://prntscr.com/juav2j

Hope this helps.

Best Regards!!