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.

expect(opListAnnotEnable.lastChunk).toEqual(true);
      const opListAnnotEnableForms = await pdfPage.getOperatorList({
        annotationMode: AnnotationMode.ENABLE_FORMS,
      });
      expect(opListAnnotEnableForms.fnArray.length).toBeGreaterThan(40);
      expect(opListAnnotEnableForms.argsArray.length).toBeGreaterThan(40);
      expect(opListAnnotEnableForms.lastChunk).toEqual(true);
      const opListAnnotEnableStorage = await pdfPage.getOperatorList({
        annotationMode: AnnotationMode.ENABLE_STORAGE,
      });
      expect(opListAnnotEnableStorage.fnArray.length).toBeGreaterThan(170);
      expect(opListAnnotEnableStorage.argsArray.length).toBeGreaterThan(170);
      expect(opListAnnotEnableStorage.lastChunk).toEqual(true);
      
      expect(opListAnnotDisable.fnArray.length).toBeLessThan(
        opListAnnotEnableForms.fnArray.length
      );
      expect(opListAnnotEnableForms.fnArray.length).toBeLessThan(
        opListAnnotEnable.fnArray.length
      );
      expect(opListAnnotEnable.fnArray.length).toBeLessThan(
        opListAnnotEnableStorage.fnArray.length
      );
      await loadingTask.destroy();
    });
    it("gets document stats after parsing page", async function () {
      const stats = await page.getOperatorList().then(function () {
        return pdfDocument.getStats();
      });
      const expectedStreamTypes = {};