Attach (recommended) or Link to PDF file here:
https://www.canada.ca/content/dam/ircc/migration/ircc/english/pdf/kits/forms/eimm5669e.pdf
[eimm5669e.pdf](https://github.com/mozilla/pdf.js/files/7225677/eimm5669e.2.pdf)

Configuration:
- Web browser and its version: Firefox nightly
- Operating system and its version: Linux Debian

Steps to reproduce the problem:
1. Look at the bottom of page 2

return (
    node.margin &&
    (node.margin.topInset ||
      node.margin.rightInset ||
      node.margin.bottomInset ||
      node.margin.leftInset)
  );
}
function _setValue(templateNode, value) {
  if (!templateNode.value) {
    const nodeValue = new Value({});
    templateNode[$appendChild](nodeValue);
    templateNode.value = nodeValue;
  }
  templateNode.value[$setValue](value);
}
function* getContainedChildren(node) {
  for (const child of node[$getChildren]()) {
    if (child instanceof SubformSet) {
      yield* child[$getContainedChildren]();
      continue;
    }
    yield child;
  }
}
function setTabIndex(node) {