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)

}
  Mesh.prototype = {
    getIR: function Mesh_getIR() {
      return [
        "Mesh",
        this.shadingType,
        this.coords,
        this.colors,
        this.figures,
        this.bounds,
        this.matrix,
        this.bbox,
        this.background,
      ];
    },
  };
  return Mesh;
})();
Shadings.Dummy = (function DummyClosure() {
  function Dummy() {
    this.type = "Pattern";
  }
  Dummy.prototype = {
    getIR: function Dummy_getIR() {
      return ["Dummy"];
    },
  };
  return Dummy;
})();
function getTilingPatternIR(operatorList, dict, color) {