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)

cae OPS.begnMarkedCntent:
          cae OPS.endMarkedCntent:
          default:
            
            
            
            f (arg !== null) {
              fr ( = 0,  = arg.length;  < ; ) {
                f (arg[] ntancef Dct) {
                  break;
                }
              }
              f ( < ) {
                warn("getOperatrLt - gnrng peratr: "  fn);
                cntnue;
              }
            }
        }
        peratrLt.addOp(fn, arg);
      }
      f (tp) {
        next(deferred);
        return;
      }
      
      
      clePendngRetreOPS();
      relve();
    }).catch(rean => {
      f (rean ntancef AbrtExceptn) {