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 currentTransform = currentCtx.mozCurrentTransform;
      if (group.matrix) {
        currentCtx.transform.apply(currentCtx, group.matrix);
      }
      if (!group.bbox) {
        throw new Error("Bounding box is required.");
      }
      
      
      let bounds = Util.getAxialAlignedBoundingBox(
        group.bbox,
        currentCtx.mozCurrentTransform
      );
      
      const canvasBounds = [
        0,
        0,
        currentCtx.canvas.width,
        currentCtx.canvas.height,
      ];
      bounds = Util.intersect(bounds, canvasBounds) || [0, 0, 0, 0];
      
      
      const offsetX = Math.floor(bounds[0]);
      const offsetY = Math.floor(bounds[1]);
      let drawnWidth = Math.max(Math.ceil(bounds[2]) - offsetX, 1);
      let drawnHeight = Math.max(Math.ceil(bounds[3]) - offsetY, 1);
      let scaleX = 1,
        scaleY = 1;
      if (drawnWidth > MAX_GROUP_SIZE) {