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)

const edges = this.edge.children.slice();
    if (edges.length < 4) {
      const defaultEdge = edges[edges.length - 1] || new Edge({});
      for (let i = edges.length; i < 4; i++) {
        edges.push(defaultEdge);
      }
    }
    const edgeStyles = edges.map(node => {
      const style = node[$toStyle]();
      style.color = style.color || "#000000";
      return style;
    });
    const widths = edges.map(edge => edge.thickness);
    const insets = [0, 0, 0, 0];
    if (this.margin) {
      insets[0] = this.margin.topInset;
      insets[1] = this.margin.rightInset;
      insets[2] = this.margin.bottomInset;
      insets[3] = this.margin.leftInset;
    }
    this[$extra] = { widths, insets };
    
    const style = Object.create(null);
    if (this.margin) {
      Object.assign(style, this.margin[$toStyle]());
    }
    if (this.fill && this.fill.presence === "visible") {