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)

pageArea = pageAreas[0];
    }
    pageArea[$extra] = {
      numberOfUse: 1,
    };
    const pageAreaParent = pageArea[$getParent]();
    pageAreaParent[$extra] = {
      numberOfUse: 1,
      pageIndex: pageAreaParent.pageArea.children.indexOf(pageArea),
      pageSetIndex: 0,
    };
    let targetPageArea;
    let leader = null;
    let trailer = null;
    let hasSomething = true;
    let hasSomethingCounter = 0;
    let startIndex = 0;
    while (true) {
      if (!hasSomething) {
        mainHtml.children.pop();
        
        if (++hasSomethingCounter === MAX_EMPTY_PAGES) {
          warn("XFA - Something goes wrong: please file a bug.");
          return mainHtml;
        }
      } else {
        hasSomethingCounter = 0;
      }
      targetPageArea = null;
      this[$extra].currentPageArea = pageArea;