Attach (recommended) or Link to PDF file here:
http://education.ohio.gov/getattachment/Topics/Special-Education/Preschool-Special-Education/ETR-Preschool-Planning-Form.pdf.aspx

- Web browser and its version: Firefox 89.0.1
- Operating system and its version: Windows 10 10.0.19043.1052
- PDF.js version: commit 5d251a3a3e7bfaa8fbfa07f0b7f9901eb3f999d9
- Is a browser extension: No

Steps to reproduce the problem:
1. Enable XFA support
2. Open form

What is the expected behavior? (add screenshot)
Shapes stay inside table cells
![image](https://user-images.githubusercontent.com/7104454/122572782-1252a580-d01c-11eb-9d0f-5fed46d6f2fe.png)

What went wrong? (add screenshot)
Shapes fall outside cells (among other issues)
![image](https://user-images.githubusercontent.com/7104454/122572885-2d251a00-d01c-11eb-8863-fa3b9969f0ea.png)

breakBeforeTarget = breakBefore.target;
    } else if (
      root.subform.children.length >= 1 &&
      root.subform.children[0].breakBefore.children.length >= 1
    ) {
      breakBefore = root.subform.children[0].breakBefore.children[0];
      breakBeforeTarget = breakBefore.target;
    } else if (root.break && root.break.beforeTarget) {
      breakBefore = root.break;
      breakBeforeTarget = breakBefore.beforeTarget;
    } else if (
      root.subform.children.length >= 1 &&
      root.subform.children[0].break &&
      root.subform.children[0].break.beforeTarget
    ) {
      breakBefore = root.subform.children[0].break;
      breakBeforeTarget = breakBefore.beforeTarget;
    }
    if (breakBefore) {
      const target = this[$searchNode](
        breakBeforeTarget,
        breakBefore[$getParent]()
      );
      if (target instanceof PageArea) {
        pageArea = target;
        
        breakBefore[$extra] = {};
      }
    }
    if (!pageArea) {