You are the first to try adding Adobe Captivate 2019 content to fixed layout EPUB using CircularFLO. As long as the code is valid HTML5 there should be little problem to add using CircularFLO's web code tools but we will need to test before advertising this feature!… Obviously there is something not quite right yet so thanks for bringing it to our attention.
Moderator: I'm sorry, but due to the rules, had to take out the links. You could contact this user by private message, or he/she probably already knows your site.
Published HTML5 output is a rather complicated folder, which is really like a website. InDesign is not meant to insert websites. I used InDesign many years ago when SWF was the default output, and it was a breeze to insert SWF published Captivate files into a digital InDesign document. Now, with the HTML5 it has become to me at least impossible. I would publish the HTML5 Captivate output, upload it to a webserver and point to the URL.