Form Submittion error

Good Day,

I have an error with my CF7 forms. When I try to complete a form it only shows the little loading arrows and does not complete the submission and therefor also does not redirect to the thank you page (i have the CF7 redirect plugin installed). But, I still get a confirmation email of the submission.

This is obviously causing an issue on my conversion tracking.
Can you assist?

The page I need help with: [log in to see the link]