Attach (recommended) or Link to PDF file here:

Configuration:
- Web browser and its version: Chrome 90.0.4430.93
- Operating system and its version: macOs Big Sur 11.2.3
- PDF.js version: 2.7.570
- Is a browser extension: No

Steps to reproduce the problem:
1. Load the attached pdf in https://mozilla.github.io/pdf.js/web/viewer.html
2. Go to page 46. Dotted lines are missing in the graphics (see screenshot from acrobat reader)

What is the expected behavior? (add screenshot) See the screenshot
[Technical_Guide_UK.pdf](https://github.com/mozilla/pdf.js/files/6413001/Technical_Guide_UK.pdf)
![Screenshot 2021-05-03 at 07 46 09](https://user-images.githubusercontent.com/3785784/116844541-a343fd80-abe3-11eb-94c3-d03b3dfd6769.png)

const dict = isStream(shading) ? shading.dict : shading;
    const type = dict.get("ShadingType");
    try {
      switch (type) {
        case ShadingType.AXIAL:
        case ShadingType.RADIAL:
          
          return new Shadings.RadialAxial(
            dict,
            matrix,
            xref,
            res,
            pdfFunctionFactory,
            localColorSpaceCache
          );
        case ShadingType.FREE_FORM_MESH:
        case ShadingType.LATTICE_FORM_MESH:
        case ShadingType.COONS_PATCH_MESH:
        case ShadingType.TENSOR_PATCH_MESH:
          return new Shadings.Mesh(
            shading,
            matrix,
            xref,
            res,
            pdfFunctionFactory,
            localColorSpaceCache
          );
        default:
          throw new FormatError("Unsupported ShadingType: " + type);
      }