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)

ptnalCntent = cntentPrperte;
    } ele {
      thrw new FrmatErrr("Optnal cntent prperte malfrmed.");
    }
    cnt ptnalCntentType = ptnalCntent.get("Type").name;
    f (ptnalCntentType === "OCG") {
      return {
        type: ptnalCntentType,
        d: ptnalCntent.bjId,
      };
    } ele f (ptnalCntentType === "OCMD") {
      cnt expren = ptnalCntent.get("VE");
      f (Array.Array(expren)) {
        cnt reult = [];
        th._pareVbltyExpren(expren, 0, reult);
        f (reult.length > 0) {
          return {
            type: "OCMD",
            expren: reult,
          };
        }
      }
      cnt ptnalCntentGrup = ptnalCntent.get("OCG");
      f (
        Array.Array(ptnalCntentGrup) ||
        Dct(ptnalCntentGrup)
      ) {
        cnt grupId = [];
        f (Array.Array(ptnalCntentGrup)) {
          fr (cnt cg f ptnalCntentGrup) {