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.

passwordIncorrectLoadingTask.onPassword = function (callback, reason) {
          if (reason === PasswordResponses.INCORRECT_PASSWORD) {
            throw new Error("Incorrect password");
          }
          
          expect(false).toEqual(true);
        };
        const result2 = passwordIncorrectLoadingTask.promise.then(
          function () {
            
            expect(false).toEqual(true);
            return Promise.reject(new Error("loadingTask should be rejected"));
          },
          function (reason) {
            expect(reason instanceof PasswordException).toEqual(true);
            expect(reason.code).toEqual(PasswordResponses.INCORRECT_PASSWORD);
            return passwordIncorrectLoadingTask.destroy();
          }
        );
        await Promise.all([result1, result2]);
      }
    );
    it("creates pdf doc from empty typed array", async function () {
      const loadingTask = getDocument(new Uint8Array(0));
      expect(loadingTask instanceof PDFDocumentLoadingTask).toEqual(true);
      try {
        await loadingTask.promise;
        
        expect(false).toEqual(true);
      } catch (reason) {