Hello @janxsch
Thank you very much for using our plugin. I visited the URL provided but your website has enabled the maintenance mode:
>> Der Wartungsmodus ist eingeschaltet
>> Site will be available soon. Thank you for your patience!
Note that if everything is OK in the form preview but not in the public website, it is because there is a third-party plugin that affects the form fields.
An alternative to prevent this interference from other plugins is to insert the form shortcode with the iframe attribute. For example, assuming your form id=1, please, insert the form shortcode as follows:
[CP_CALCULATED_FIELDS id="1" iframe="1"]Best regards.