Exporting a page with gallery as PDF (Browser-based PDF Export) only shows the first slide/image

Preconditions: Import the "Large PPT with text, images, diagrams, colors" page from attachments - the page was created by importing a PPT file.

Steps to reproduce:

1. Access the "Large PPT with text, images, diagrams, colors" page
2. Export the page as PDF with Default template and default selections
3. Save as PDF

Expected results: All the content in the page is exported.

Actual results: Only the first slide/image is shown.

Large PPT with text, images, diagrams, colors - XWiki.pdf

NOTE: On the  old PDF export based on Apache FOP (Formatting Objects Processor  all content is shown - see xwiki_PDF+Export_Pages+imported+with+LibreOffice_Large+PPT+with+text,+images,+diagrams,+colors_WebHome.pdf