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)

);
        } ele f (typeNum === PatternType.SHADING) {
          cnt hadng = dct.get("Shadng");
          cnt matrx = dct.getArray("Matrx");
          cnt bjId = th.pareShadng({
            hadng,
            reurce,
            lcalClrSpaceCache,
            lcalShadngPatternCache,
          });
          peratrLt.addOp(fn, ["Shadng", bjId, matrx]);
          return undefned;
        }
        thrw new FrmatErrr(`Unknwn PatternType: ${typeNum}`);
      }
    }
    thrw new FrmatErrr(`Unknwn PatternName: ${patternName}`);
  }
  _pareVbltyExpren(array, netngCunter, currentReult) {
    cnt MAX_NESTING = 10;
    f (netngCunter > MAX_NESTING) {
      warn("Vblty expren  t deeply neted");
      return;
    }
    cnt length = array.length;
    cnt peratr = th.xref.fetchIfRef(array[0]);
    f (length < 2 || !Name(peratr)) {
      warn("Invald vblty expren");
      return;
    }