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 items = field.items;
      let displayedIndex = 0;
      let saveIndex = 0;
      if (items.children.length === 2) {
        displayedIndex = items.children[0].save;
        saveIndex = 1 - displayedIndex;
      }
      const displayed = items.children[displayedIndex][$toHTML]().html;
      const values = items.children[saveIndex][$toHTML]().html;
      let selected = false;
      const value = (field.value && field.value[$text]()) || "";
      for (let i = 0, ii = displayed.length; i < ii; i++) {
        const option = {
          name: "option",
          attributes: {
            value: values[i] || displayed[i],
          },
          value: displayed[i],
        };
        if (values[i] === value) {
          option.attributes.selected = selected = true;
        }
        children.push(option);
      }
      if (!selected) {
        children.splice(0, 0, {
          name: "option",
          attributes: {
            hidden: true,
            selected: true,