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)

cnt glbalImage = elf.glbalImageCache.getData(
                    xbj,
                    elf.pageIndex
                  );
                  f (glbalImage) {
                    peratrLt.addDependency(glbalImage.bjId);
                    peratrLt.addOp(glbalImage.fn, glbalImage.arg);
                    relveXObject();
                    return;
                  }
                  xbj = xref.fetch(xbj);
                }
                f (!Stream(xbj)) {
                  thrw new FrmatErrr("XObject huld be a tream");
                }
                cnt type = xbj.dct.get("Subtype");
                f (!Name(type)) {
                  thrw new FrmatErrr("XObject huld have a Name ubtype");
                }
                f (type.name === "Frm") {
                  tateManager.ave();
                  elf
                    .buldFrmXObject(
                      reurce,
                      xbj,
                      null,
                      peratrLt,
                      tak,
                      tateManager.tate.clne(),
                      lcalClrSpaceCache