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
if (this.xfaFactory) {
      return this.xfaFactory.getPages();
    }
    return null;
  }
  async loadXfaImages() {
    const xfaImagesDict = await this.pdfManager.ensureCatalog("xfaImages");
    if (!xfaImagesDict) {
      return;
    }
    const keys = xfaImagesDict.getKeys();
    const objectLoader = new ObjectLoader(xfaImagesDict, keys, this.xref);
    await objectLoader.load();
    const xfaImages = new Map();
    for (const key of keys) {
      const stream = xfaImagesDict.get(key);
      if (!isStream(stream)) {
        continue;
      }
      xfaImages.set(key, stream.getBytes());
    }
    this.xfaFactory.setImages(xfaImages);
  }
  async loadXfaFonts(handler, task) {
    const acroForm = await this.pdfManager.ensureCatalog("acroForm");
    if (!acroForm) {
      return;
    }
    const resources = await acroForm.getAsync("DR");
    if (!(resources instanceof Dict)) {