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)

ctx.fillText(character, x, y);
        }
        if (
          fillStrokeMode === TextRenderingMode.STROKE ||
          fillStrokeMode === TextRenderingMode.FILL_STROKE
        ) {
          if (resetLineWidthToOne) {
            ctx.save();
            ctx.moveTo(x, y);
            ctx.resetTransform();
            ctx.lineWidth = Math.round(this._combinedScaleFactor);
            ctx.strokeText(character, 0, 0);
            ctx.restore();
          } else {
            ctx.strokeText(character, x, y);
          }
        }
      }
      if (isAddToPathSet) {
        const paths = this.pendingTextPaths || (this.pendingTextPaths = []);
        paths.push({
          transform: ctx.mozCurrentTransform,
          x,
          y,
          fontSize,
          addToPath,
        });
      }
    }
    get isFontSubpixelAAEnabled() {