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.
const [selStart, selEnd] = detail.selRange;
              if (selStart >= 0 && selEnd < event.target.value.length) {
                event.target.setSelectionRange(selStart, selEnd);
              }
            },
          };
          Object.keys(detail)
            .filter(name => name in actions)
            .forEach(name => actions[name]());
          this._setColor(event);
        });
        
        
        element.addEventListener("keydown", event => {
          elementData.beforeInputValue = event.target.value;
          
          
          let commitKey = -1;
          if (event.key === "Escape") {
            commitKey = 0;
          } else if (event.key === "Enter") {
            commitKey = 2;
          } else if (event.key === "Tab") {
            commitKey = 3;
          }
          if (commitKey === -1) {
            return;
          }