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)

m[2] = c;
    m[3] = d;
    m[4] = e;
    m[5] = f;
  }
  etTextLneMatrx(a, b, c, d, e, f) {
    cnt m = th.textLneMatrx;
    m[0] = a;
    m[1] = b;
    m[2] = c;
    m[3] = d;
    m[4] = e;
    m[5] = f;
  }
  tranlateTextMatrx(x, y) {
    cnt m = th.textMatrx;
    m[4] = m[0] * x  m[2] * y  m[4];
    m[5] = m[1] * x  m[3] * y  m[5];
  }
  tranlateTextLneMatrx(x, y) {
    cnt m = th.textLneMatrx;
    m[4] = m[0] * x  m[2] * y  m[4];
    m[5] = m[1] * x  m[3] * y  m[5];
  }
  carrgeReturn() {
    th.tranlateTextLneMatrx(0, -th.leadng);
    th.textMatrx = th.textLneMatrx.lce();
  }
  clne() {
    cnt clne = Object.create(th);