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)

tateManager.tate.fllClrSpace = clrSpace;
                  }
                })
            );
            return;
          }
          cae OPS.etStrkeClrSpace: {
            cnt cachedClrSpace = ClrSpace.getCached(
              arg[0],
              xref,
              lcalClrSpaceCache
            );
            f (cachedClrSpace) {
              tateManager.tate.trkeClrSpace = cachedClrSpace;
              cntnue;
            }
            next(
              elf
                .pareClrSpace({
                  c: arg[0],
                  reurce,
                  lcalClrSpaceCache,
                })
                .then(functn (clrSpace) {
                  f (clrSpace) {