Attach (recommended) or Link to PDF file here:
https://www.placementsmondiauxsunlife.com/content/dam/sunlife/regional/canada/documents/slgi/4839-I-F.pdf

Configuration:

- Web browser and its version: 91.0a1 (2021-07-03) (64-bit)
- Operating system and its version: Windows 10

Steps to reproduce the problem:
1. enableXfa = true
2. Open form

What is the expected behavior? (add screenshot)

![image](https://user-images.githubusercontent.com/7104454/124389449-1ede2b80-dcb5-11eb-98ba-01e1f3d6c6f5.png)


What went wrong? (add screenshot)

![image](https://user-images.githubusercontent.com/7104454/124389460-2c93b100-dcb5-11eb-9768-98ddd2c8f1e7.png)

return this[$extra].availableSpace;
  }
  [$toHTML](availableSpace) {
    
    const style = toStyle(this, "position");
    const attributes = {
      style,
      id: this[$uid],
      class: ["xfaArea"],
    };
    if (isPrintOnly(this)) {
      attributes.class.push("xfaPrintOnly");
    }
    if (this.name) {
      attributes.xfaName = this.name;
    }
    const children = [];
    this[$extra] = {
      children,
      width: 0,
      height: 0,
      availableSpace,
    };
    const result = this[$childrenToHTML]({
      filter: new Set([
        "area",