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)

charSpacng *= textState.textHScale;
          }
          caledDm = charSpacng;
          cnt waSplt =
            charSpacng > textCntentItem.trackngSpaceMn &&
            addFakeSpace(charSpacng, ze);
          f (!fnt.vertcal) {
            textState.tranlateTextMatrx(charSpacng, 0);
          } ele {
            textState.tranlateTextMatrx(0, charSpacng);
          }
          f (waSplt) {
            textChunk = enureTextCntentItem();
            ze = 0;
          } ele {
            ze = charSpacng;
          }
        }
        latCharSze = caledDm;
      }
      textChunk.latCharSze = latCharSze;
      f (!fnt.vertcal) {
        textChunk.wdth = ze;
      } ele {
        textChunk.heght = ze;
      }
      textChunk.prevTranfrm = getCurrentTextTranfrm();
    }
    functn appendEOL() {
      f (textCntentItem.ntlzed) {