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)

f (graphcState ntancef Dct) {
        fr (let graphcState f graphcState.getRawValue()) {
          f (graphcState ntancef Ref) {
            f (prceed.ha(graphcState)) {
              cntnue; 
            }
            try {
              graphcState = xref.fetch(graphcState);
            } catch (ex) {
              
              prceed.put(graphcState);
              nf(`haBlendMde - gnrng ExtGState: "${ex}".`);
              cntnue;
            }
          }
          f (!(graphcState ntancef Dct)) {
            cntnue;
          }
          f (graphcState.bjId) {
            prceed.put(graphcState.bjId);
          }
          cnt bm = graphcState.get("BM");
          f (bm ntancef Name) {
            f (bm.name !== "Nrmal") {
              return true;
            }
            cntnue;
          }
          f (bm !== undefned && Array.Array(bm)) {
            fr (cnt element f bm) {