The PDF table of contents doesn't show heading numbers

Follow these steps to reproduce:

• Install https://extensions.xwiki.org/xwiki/bin/view/Extension/Numbered%20Content/Numbered%20Headings%20Application/
• Install https://extensions.xwiki.org/xwiki/bin/view/Extension/Numbered%20Content/Numbered%20Headings%20Application/ToC%20Macro/
• Create a wiki page with this content

  {{toc/}}
  
  = Header 1 =
  
  == Header 1.1 ==
  
  (% data-xwiki-rendering-protected="true" %)
  === Header without number ===
  
  === Header 1.1.1 ===
  
  (% data-numbered-headings-start="10" style="--numbered-headings-start: 9;" %)
  == Header 1.10 ==
  

• Activate numbered headings for this page
• Export the page to PDF with the table of contents option checked

Expected result: the PDF table of contents shows the heading numbers, as it happens when the table of contents macro is called within the exported content.

Actual result: the heading numbers are shown only when the table of contents macro is called within the exported content.