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)

if (!this.value) {
      return HTMLResult.EMPTY;
    }
    const value = this.value[$toHTML](availableSpace).html;
    if (!value) {
      return HTMLResult.EMPTY;
    }
    const savedReserve = this.reserve;
    if (this.reserve <= 0) {
      const { w, h } = this[$getExtra](availableSpace);
      switch (this.placement) {
        case "left":
        case "right":
        case "inline":
          this.reserve = w;
          break;
        case "top":
        case "bottom":
          this.reserve = h;
          break;
      }
    }
    const children = [];
    if (typeof value === "string") {
      children.push({
        name: "#text",
        value,
      });
    } else {