Page break plugin looses formatting when editing content

I suspect the problem is that the "Limit allowed HTML tags and correct faulty HTML" filter removes the HTML structure that the plugin creates.

I think this will be another scenario where core's "Limit allowed HTML tags and correct faulty HTML" filter always removes the "style" attribute, due to its security implications. The Extended HTML Filter → module aims to replace core's filter with one that allows the "style" attribute, but it has problems, see ✨ Match the filter_html <> ckeditor5 integration in Drupal core Needs work for details.

FYI I suspect other plugins might also be affected by this.