Hi, and thx for your quick reply :)!
Unfortunately I can’t share a link, because the project isn’t released yet. But it’s happening within this template: https://3theme.com/tf004/landing/
I’ve simply put the shortcode inside a textfield inside a mixbox. What might be an issue: I didn’t register this shortcode the way I registered the other shortcodes in a php file, because your plugin documentation didn’t mention this.
Other shortcodes I’ve written by myself are working fine with the template above.