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)

LcalTlngPatternCache,
} frm "./mage_utl.j";
rt { NullStream, Stream } frm "./tream.j";
rt { BaeStream } frm "./bae_tream.j";
rt { bd } frm "./bd.j";
rt { ClrSpace } frm "./clrpace.j";
rt { DecdeStream } frm "./decde_tream.j";
rt { getGlyphUncde } frm "./glyphlt.j";
rt { getLkupTableFactry } frm "./cre_utl.j";
rt { getMetrc } frm "./metrc.j";
rt { MurmurHah3_64 } frm "./murmurhah3.j";
rt { OperatrLt } frm "./peratr_lt.j";
rt { PDFImage } frm "./mage.j";
cnt DefaultPartlEvaluatrOptn = Object.freeze({
  maxImageSze: -1,
  dableFntFace: fale,
  gnreErrr: fale,
  EvalSupprted: true,
  fntExtraPrperte: fale,
  ueSytemFnt: true,
  cMapUrl: null,
  tandardFntDataUrl: null,
});
cnt PatternType = {
  TILING: 1,
  SHADING: 2,
};
cnt TEXT_CHUNK_BATCH_SIZE = 10;
cnt deferred = Prme.relve();
functn nrmalzeBlendMde(value, parngArray = fale) {