Attach (recommended) or Link to PDF file here:
[multiple.pdf](https://github.com/mozilla/pdf.js/files/6344777/multiple.pdf)

Steps to reproduce the problem:
1. Write something in a field

What is the expected behavior? (add screenshot)
The 3 fields must have the same value

What went wrong? (add screenshot)
The 2 other fields are empty

The three fields share the same name `Text3`.
It works as expected in Adobe and Chrome.
while (selectElement.length !== 0) {
              selectElement.remove(0);
            }
            storage.setValue(id, { value: null, items: [] });
          },
          insert() {
            const { index, displayValue, exportValue } = detail.insert;
            const optionElement = document.createElement("option");
            optionElement.textContent = displayValue;
            optionElement.value = exportValue;
            selectElement.insertBefore(
              optionElement,
              selectElement.children[index]
            );
            storage.setValue(id, {
              value: getValue(event,  true),
              items: getItems(event),
            });
          },
          items() {