https://boersengefluester.de/wp-content/uploads/assets/annuals/2019/578560.pdf

Configuration:
- PDF.js version: 2.7.570

Steps to reproduce the problem:
1. Load the linked PDF
2. On the second page, highlight the word "Mitarbeiterinnen" by double-clicking it

What is the expected behavior?
The word should be recognized as a single word and highlighted as such.

What went wrong?
Instead, it's recognized as 3 words: "Mit", "arbei", "terinnen"
![image](https://user-images.githubusercontent.com/5265630/114384414-f8fe2a80-9b8e-11eb-8843-5099425b0fad.png)

This happens for many words in this PDF.

Is there anything that can be changed in how I use pdfjs-dist to make it recognize this as a single word? Just looking at the PDF, I can't tell what would cause this behavior.

await loadingTask.destroy();
    });
    it("gets operator list", async function () {
      const operatorList = await page.getOperatorList();
      expect(operatorList.fnArray.length).toBeGreaterThan(100);
      expect(operatorList.argsArray.length).toBeGreaterThan(100);
      expect(operatorList.lastChunk).toEqual(true);
    });
    it("gets operatorList with JPEG image (issue 4888)", async function () {
      const loadingTask = getDocument(buildGetDocumentParams("cmykjpeg.pdf"));
      const pdfDoc = await loadingTask.promise;
      const pdfPage = await pdfDoc.getPage(1);
      const operatorList = await pdfPage.getOperatorList();
      const imgIndex = operatorList.fnArray.indexOf(OPS.paintImageXObject);
      const imgArgs = operatorList.argsArray[imgIndex];
      const { data } = pdfPage.objs.get(imgArgs[0]);
      expect(data instanceof Uint8ClampedArray).toEqual(true);
      expect(data.length).toEqual(90000);
      await loadingTask.destroy();
    });
    it(
      "gets operatorList, from corrupt PDF file (issue 8702), " +
        "with/without `stopAtErrors` set",
      async function () {
        const loadingTask1 = getDocument(
          buildGetDocumentParams("issue8702.pdf", {
            stopAtErrors: false, 
          })
        );
        const loadingTask2 = getDocument(