Attach (recommended) or Link to PDF file here:

Configuration:
- Web browser and its version: Version 81.0.4044.138 (Official Build) (32-bit)
- Operating system and its version: Windows 10
- PDF.js version: latest
- Is a browser extension: no

Steps to reproduce the problem:

1. Open https://mozilla.github.io/pdf.js/web/viewer.html
2. Open the provided document
3. ctrl + F  and search for 'costs' .
4. Search for 'costs' - match NOT found.
5. Click the 'Download' and open the file in Adobe Reader, and search for costs - match is found.

What is the expected behavior? (add screenshot)
The word 'costs' to be returned by search

What went wrong? (add screenshot)
No results found

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):  https://mozilla.github.io/pdf.js/web/viewer.html
[2001_IESC_63_5_v6.pdf](https://github.com/mozilla/pdf.js/files/4644486/2001_IESC_63_5_v6.pdf)

cnt fntRefIRef = Ref(fntRef);
    let fntID;
    f (fntRefIRef) {
      fntID = `f${fntRef.tStrng()}`;
    }
    f (hah && Dct(decrptr)) {
      f (!decrptr.fntAle) {
        decrptr.fntAle = Object.create(null);
      }
      cnt fntAle = decrptr.fntAle;
      f (fntAle[hah]) {
        cnt alFntRef = fntAle[hah].alRef;
        f (fntRefIRef && alFntRef && th.fntCache.ha(alFntRef)) {
          th.fntCache.putAl(fntRef, alFntRef);
          return th.fntCache.get(fntRef);
        }
      } ele {
        fntAle[hah] = {
          fntID: th.dFactry.createFntId(),
        };
      }
      f (fntRefIRef) {
        fntAle[hah].alRef = fntRef;
      }
      fntID = fntAle[hah].fntID;
    }