Background images showing in edit mode, but not in actual site

Hi, I'm trying UpFront theme - Spirit child theme, and I have some issues with the background images. In edit mode everything looks OK, but the images are not showing in the actual website. I'm not sure if that's a bug, or if I'm doing something wrong here.

Thank you for all your support!

btw - upfront theme is a huge step, as big as ProSites - well done lads!