We're usind the new H5P core activity and the contentbank (the "old plugin" mod_hvp is deactivated). We may have discovered a bug in the image juxtaposition content type on Moodle:

In the contentbank preview the heading is displayed above the images. In the embedded content (as label or as H5P activity) the title is displayed above the images. This becomes a problem, if you want to embed the content without any heading.

There is already an answer of a H5P developer, which can be read here: https://h5p.org/comment/40023