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)

} else if (target instanceof ContentArea) {
            const index = contentAreas.findIndex(e => e === target);
            if (index !== -1) {
              i = index - 1;
            } else {
              targetPageArea = target[$getParent]();
              startIndex =
                targetPageArea.contentArea.children.findIndex(
                  e => e === target
                ) - 1;
            }
          }
          continue;
        }
        flush(i);
      }
      this[$extra].pageNumber += 1;
      if (targetPageArea) {
        if (targetPageArea[$isUsable]()) {
          targetPageArea[$extra].numberOfUse += 1;
        } else {
          targetPageArea = null;
        }
      }
      pageArea = targetPageArea || pageArea[$getNextPage]();
    }
  }
}
class Text extends ContentObject {
  constructor(attributes) {