Gravityview Datatables and Upfront? Do they love each other?

Hello,

First I would love declare my love for you guess. Upfront and your plugins are awesome. But now I've got a little issue.

I want to display a (user input generated) list of books on my website. I already used Gravity forms so I bought Gravityview. The Datatables extentsion is great for my goal.

But... nothing shows. In normal table view everything displays fine. But in Datatable view only this appears.

No. Books. :cry:

I run Cloudflare (free) and WPRocket, so I excluded the page from caching ed. But nothing happend. Can you help me out? This is the link: http://bit.ly/2c2GXEb

Support acces is turned on!