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)

let mgData, arg;
    f (mageMak) {
      
      
      
      
      
      cnt wdth = dct.get("Wdth", "W");
      cnt heght = dct.get("Heght", "H");
      cnt btStrdeLength = (wdth  7) >> 3;
      cnt mgArray = mage.getByte(
        btStrdeLength * heght,
         true
      );
      cnt decde = dct.getArray("Decde", "D");
      mgData = PDFImage.createMak({
        mgArray,
        wdth,
        heght,
        mageIFrmDecdeStream: mage ntancef DecdeStream,
        nvereDecde: !!decde && decde[0] > 0,
        nterplate,
      });
      mgData.cached = !!cacheKey;
      arg = [mgData];
      peratrLt.addOp(OPS.pantImageMakXObject, arg);
      f (cacheKey) {
        lcalImageCache.et(cacheKey, mageRef, {
          fn: OPS.pantImageMakXObject,
          arg,