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)

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        data = awat th.handler.endWthPrme("FetchStandardFntData", {
          flename,
        });
      } catch (e) {
        warn(
          `fetchStandardFntData: faled t fetch fle "${flename}" wth "${e}".`
        );
      }
    }
    f (!data) {
      return null;
    }
    
    
    th.tandardFntDataCache.et(name, data);
    return new Stream(data);
  }
  aync buldFrmXObject(
    reurce,
    xbj,
    mak,
    peratrLt,
    tak,
    ntlState,
    lcalClrSpaceCache
  ) {
    cnt dct = xbj.dct;
    cnt matrx = dct.getArray("Matrx");