Attach (recommended) or Link to PDF file here:
[backgroundimage_not_visible_anonymisiert.pdf](https://github.com/mozilla/pdf.js/files/6544725/backgroundimage_not_visible_anonymisiert.pdf)


Configuration:
- Web browser and its version: Chrome Version 90.0.4430.212 (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 the document in demo viewer.js
2.

What is the expected behavior? (add screenshot)
The backgroundimage gets rendered like in Acrobat Reader
<img width="1348" alt="Bildschirmfoto 2021-05-26 um 09 44 21" src="https://user-images.githubusercontent.com/1286150/119621970-00a82480-be07-11eb-8fed-f74ac04b840b.png">

What went wrong? (add screenshot)
Backgroundimage is not rendered only some  text
<img width="987" alt="Bildschirmfoto 2021-05-26 um 09 43 57" src="https://user-images.githubusercontent.com/1286150/119621938-fab24380-be06-11eb-92ac-4ecb2c9334b1.png">




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

const ctx = this.ctx;
      const current = this.current;
      const font = current.font;
      const fontSize = current.fontSize;
      const fontDirection = current.fontDirection;
      const spacingDir = font.vertical ? 1 : -1;
      const charSpacing = current.charSpacing;
      const wordSpacing = current.wordSpacing;
      const textHScale = current.textHScale * fontDirection;
      const fontMatrix = current.fontMatrix || FONT_IDENTITY_MATRIX;
      const glyphsLength = glyphs.length;
      const isTextInvisible =
        current.textRenderingMode === TextRenderingMode.INVISIBLE;
      let i, glyph, width, spacingLength;
      if (isTextInvisible || fontSize === 0) {
        return;
      }
      this._cachedGetSinglePixelWidth = null;
      ctx.save();
      ctx.transform.apply(ctx, current.textMatrix);
      ctx.translate(current.x, current.y);
      ctx.scale(textHScale, fontDirection);
      for (i = 0; i < glyphsLength; ++i) {
        glyph = glyphs[i];