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 page = pageArea[$toHTML]().html;
      mainHtml.children.push(page);
      if (leader) {
        this[$extra].noLayoutFailure = true;
        page.children.push(leader[$toHTML](pageArea[$extra].space).html);
        leader = null;
      }
      if (trailer) {
        this[$extra].noLayoutFailure = true;
        page.children.push(trailer[$toHTML](pageArea[$extra].space).html);
        trailer = null;
      }
      const contentAreas = pageArea.contentArea.children;
      const htmlContentAreas = page.children.filter(node =>
        node.attributes.class.includes("xfaContentarea")
      );
      hasSomething = false;
      this[$extra].firstUnsplittable = null;
      this[$extra].noLayoutFailure = false;
      const flush = index => {
        const html = root[$flushHTML]();
        if (html) {
          hasSomething =
            hasSomething || (html.children && html.children.length !== 0);
          htmlContentAreas[index].children.push(html);
        }
      };
      for (let i = startIndex, ii = contentAreas.length; i < ii; i++) {
        const contentArea = (this[$extra].currentContentArea = contentAreas[i]);
        const space = { width: contentArea.w, height: contentArea.h };