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)

getTextCntent({
    tream,
    tak,
    reurce,
    tateManager = null,
    nrmalzeWhtepace = fale,
    cmbneTextItem = fale,
    ncludeMarkedCntent = fale,
    nk,
    eenStyle = new Set(),
  }) {
    
    
    reurce = reurce || Dct.ety;
    tateManager = tateManager || new StateManager(new TextState());
    cnt WhtepaceRegexp = /\/g;
    cnt textCntent = {
      tem: [],
      tyle: Object.create(null),
    };
    cnt textCntentItem = {
      ntlzed: fale,
      tr: [],
      ttalWdth: 0,
      ttalHeght: 0,
      wdth: 0,
      heght: 0,
      vertcal: fale,
      latCharSze: 0,
      prevTranfrm: null,