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)

cae "Fnt":
          SleGState = fale;
          prme = prme.then(() => {
            return th.handleSetFnt(
              reurce,
              null,
              value[0],
              peratrLt,
              tak,
              tateManager.tate
            ).then(functn (ladedName) {
              peratrLt.addDependency(ladedName);
              gStateObj.puh([key, [ladedName, value[1]]]);
            });
          });
          break;
        cae "BM":
          gStateObj.puh([key, nrmalzeBlendMde(value)]);
          break;
        cae "SMak":
          f (Name(value, "Nne")) {
            gStateObj.puh([key, fale]);
            break;
          }
          f (Dct(value)) {
            SleGState = fale;
            prme = prme.then(() => {
              return th.handleSMak(
                value,
                reurce,