Attach (recommended) or Link to PDF file here:
http://help.adobe.com/en_US/livecycle/11.0/SampleForms/941/Form.pdf

- Web browser and its version: Firefox 89.0.1
- Operating system and its version: Windows 10 10.0.19043.1052
- PDF.js version: commit bdfcdd6f8326f22c135edfa29a341ea4c558f3d1
- Is a browser extension: No

Steps to reproduce the problem:
1. Enable XFA support
2. Open form

What is the expected behavior? (add screenshot)
Page 3 (of 4) renders
![image](https://user-images.githubusercontent.com/7104454/122686842-622e9980-d1e1-11eb-92ab-86fe488560f2.png)

What went wrong? (add screenshot)
Only 3 pages total render in pdf.js
return `g_${pdfManager.docId}`;
      }
      static createFontId() {
        return `f${++idCounters.font}`;
      }
      static createObjId() {
        unreachable("Abstract method `createObjId` called.");
      }
      static getPageObjId() {
        unreachable("Abstract method `getPageObjId` called.");
      }
    };
  }
  parse(recoveryMode) {
    this.xref.parse(recoveryMode);
    this.catalog = new Catalog(this.pdfManager, this.xref);
    
    
    
    
    if (this.catalog.version) {
      this._version = this.catalog.version;
    }
  }
  get linearization() {