When converting an HTML document to PDF using the QT WebEngine (or Chromium headless), the first <br> tag inside a <li> element is consistently ignored. This results in missing line breaks in the generated PDF. The issue does not occur in browser rendering, only during PDF export.

Steps to reproduce:

1. Create an HTML file with:
   {{<ul>
   <li>test<br>Text with expected line break</li>
   </ul>}}
2. Convert the file to PDF using QT WebEngine or Chrome headless.
3. Observe that the <br> is ignored in the output PDF.

Workaround:
Inserting a dummy <br> tag before the <ul> (e.g. <br style="display:none">) causes the first <br> inside <li> to be respected during PDF rendering.

Expected behavior:
All <br> tags should be respected during PDF conversion, regardless of their position.