Attach (recommended) or Link to PDF file here:
[Testfile v1.5 to PDFA2.pdf](https://github.com/mozilla/pdf.js/files/6310752/Testfile.v1.5.to.PDFA2.pdf)


Configuration:
- Web browser and its version: Version 89.0.4389.114 (Offizieller Build) (x86_64)
- Operating system and its version: Windows 10 / MacOS BigSur
- PDF.js version: 2.5.207
- Is a browser extension: no 

Steps to reproduce the problem:
1.  Open Testfile v1.5 to PDFA2.pdf in pdf.js viewer demo
2. text is covered up by markings / highlights which are stored in pdf itself

What is the expected behavior? (add screenshot)
Should be displayed as in Acrobat Reader
<img width="1169" alt="Bildschirmfoto 2021-04-14 um 14 24 41" src="https://user-images.githubusercontent.com/1286150/114710202-bf175a80-9d2d-11eb-8d54-75481fe91b7d.png">

What went wrong? (add screenshot)
It's how it is displayed in pdf.js viewer
<img width="782" alt="Bildschirmfoto 2021-04-14 um 14 24 16" src="https://user-images.githubusercontent.com/1286150/114710311-d8200b80-9d2d-11eb-8000-b67b94488929.png">

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):

(x < rect[0] || x > rect[2] || y < rect[1] || y > rect[3])
      ) {
        return null;
      }
      quadPointsLists[i].push({ x, y });
    }
  }
  
  
  
  
  
  
  
  
  
  
  
  
  return quadPointsLists.map(quadPointsList => {
    const [minX, maxX, minY, maxY] = quadPointsList.reduce(
      ([mX, MX, mY, MY], quadPoint) => [
        Math.min(mX, quadPoint.x),
        Math.max(MX, quadPoint.x),
        Math.min(mY, quadPoint.y),
        Math.max(MY, quadPoint.y),
      ],
      [Number.MAX_VALUE, Number.MIN_VALUE, Number.MAX_VALUE, Number.MIN_VALUE]
    );
    return [