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
isString,
  OPS,
  PageActionEventType,
  shadow,
  stringToBytes,
  stringToPDFString,
  stringToUTF8String,
  unreachable,
  Util,
  warn,
} from "../shared/util.js";
import {
  clearPrimitiveCaches,
  Dict,
  isDict,
  isName,
  isRef,
  isStream,
  Name,
  Ref,
} from "./primitives.js";
import {
  collectActions,
  getInheritableProperty,
  isWhiteSpace,
  MissingDataException,
  validateCSSFont,
  XRefEntryException,
  XRefParseException,
} from "./core_utils.js";