Attach (recommended) or Link to PDF file here:
[0 NIF MODELO 30.pdf](https://github.com/mozilla/pdf.js/files/7187486/0.NIF.MODELO.30.2.pdf)

Configuration:
- Web browser and its version: firefox nightly
- Operating system and its version: linux debian

Steps to reproduce the problem:
1. Open the PDF
2. Click on the button  `Rellenar Formulario` (top right of the first page)
3. There is the pop-up "Stay... or Leave...`.

It's a bit annoying from the user pov and it doesn't make sense (nobody wants to leave the form but just reset it)

It works fine when replacing  `""` by `"#"` here:
https://github.com/mozilla/pdf.js/blob/7082ff9bf876b98fbda118cdbd6267d3c0df6948/src/display/annotation_layer.js#L483

@Snuffleupagus, you changed this few month ago:
https://github.com/mozilla/pdf.js/commit/e2b6d79dee9ffd2aba715d6b3cb8fa143d86153c

do you have some ideas ?
selEnd: event.target.selectionEnd,
              },
            });
          }
          _blurListener(event);
        });
        element.addEventListener("mousedown", event => {
          elementData.beforeInputValue = event.target.value;
          elementData.beforeInputSelectionRange = null;
        });
        element.addEventListener("keyup", event => {
          
          if (event.target.selectionStart === event.target.selectionEnd) {
            elementData.beforeInputSelectionRange = null;
          }
        });
        element.addEventListener("select", event => {
          elementData.beforeInputSelectionRange = [
            event.target.selectionStart,
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        });
        if (this.data.actions?.Keystroke) {
          
          
          element.addEventListener("input", event => {
            let selStart = -1;
            let selEnd = -1;
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