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.

const page1 = loadingTask.promise.then(function (pdfDoc) {
        return pdfDoc.getPage(1).then(
          function (pdfPage) {
            expect(pdfPage instanceof PDFPageProxy).toEqual(true);
            expect(pdfPage.ref).toEqual({ num: 6, gen: 0 });
          },
          function (reason) {
            throw new Error("shall not fail for valid page");
          }
        );
      });
      const page2 = loadingTask.promise.then(function (pdfDoc) {
        return pdfDoc.getPage(2).then(
          function (pdfPage) {
            throw new Error("shall fail for invalid page");
          },
          function (reason) {
            expect(reason instanceof Error).toEqual(true);
            expect(reason.message).toEqual(
              "Pages tree contains circular reference."
            );
          }
        );
      });
      await Promise.all([page1, page2]);
      await loadingTask.destroy();
    });
    it("gets page index", async function () {
      const ref = { num: 17, gen: 0 }; 
      const pageIndex = await pdfDocument.getPageIndex(ref);