Hey Maarten,
Thanks for posting, and for using our plugins.
Since the issue seems to be isolated to a conflict with your theme, I’d suggest reaching out to their developers for support with this issue, as we, unfortunately, can’t support theme and plugin conflicts on this forum. We use this forum to support issues with our plugins out of the box, as configured with the latest version of WordPress, WordPress default themes, and the rest of our plugin suite.
Best of luck with your project! I’ll leave this open in case any other users, who might be using that theme as well, are able to provide you with any tips. Thanks for understanding & let us know should you have any questions in the future!
Best,
Shelby ?