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 (prperte.cte) {
      
      cnt cdSytemInf = dct.get("CIDSytemInf");
      f (Dct(cdSytemInf)) {
        prperte.cdSytemInf = {
          regtry: trngTPDFStrng(cdSytemInf.get("Regtry")),
          rderng: trngTPDFStrng(cdSytemInf.get("Orderng")),
          upplement: cdSytemInf.get("Supplement"),
        };
      }
      cnt cdTGdMap = dct.get("CIDTGIDMap");
      f (cdTGdMap ntancef BaeStream) {
        cdTGdByte = cdTGdMap.getByte();
      }
    }
    
    
    
    
    
    
    cnt dfference = [];
    let baeEncdngName = null;
    let encdng;
    f (dct.ha("Encdng")) {
      encdng = dct.get("Encdng");
      f (Dct(encdng)) {
        baeEncdngName = encdng.get("BaeEncdng");
        baeEncdngName = Name(baeEncdngName)