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)

operatorList,
      executionStartIdx,
      continueCallback,
      stepper
    ) {
      const argsArray = operatorList.argsArray;
      const fnArray = operatorList.fnArray;
      let i = executionStartIdx || 0;
      const argsArrayLen = argsArray.length;
      
      if (argsArrayLen === i) {
        return i;
      }
      const chunkOperations =
        argsArrayLen - i > EXECUTION_STEPS &&
        typeof continueCallback === "function";
      const endTime = chunkOperations ? Date.now() + EXECUTION_TIME : 0;
      let steps = 0;
      const commonObjs = this.commonObjs;
      const objs = this.objs;
      let fnId;
      while (true) {
        if (stepper !== undefined && i === stepper.nextBreakPoint) {
          stepper.breakIt(i, continueCallback);
          return i;
        }
        fnId = fnArray[i];
        if (fnId !== OPS.dependency) {
          this[fnId].apply(this, argsArray[i]);