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)

parent.layout &&
      parent.layout.endsWith("-tb") &&
      parent[$extra].numberInLine !== 0
    ) {
      
      
      
      
      
      
      return false;
    }
    this[$extra]._isSplittable = true;
    return true;
  }
  [$toHTML](availableSpace) {
    if (this.break) {
      
      
      if (this.break.after !== "auto" || this.break.afterTarget !== "") {
        const node = new BreakAfter({
          targetType: this.break.after,
          target: this.break.afterTarget,
          startNew: this.break.startNew.toString(),
        });
        node[$globalData] = this[$globalData];
        this[$appendChild](node);
        this.breakAfter.push(node);
      }
      if (this.break.before !== "auto" || this.break.beforeTarget !== "") {