Attach (recommended) or Link to PDF file here:
[docOficialPDF.php.pdf](https://github.com/mozilla/pdf.js/files/7159923/docOficialPDF.php.pdf)

Configuration:
- Web browser and its version: Firefox nightly
- Operating system and its version: linux debian
- PDF.js version: built-in viewer
- Is a browser extension: no

Steps to reproduce the problem:
1. Open the pdf page 2
2. Checkbox "Alta" in section 2 must be checked

It works fine with evince.
if (this.data.checkBox) {
      return this._saveCheckbox(evaluator, task, annotationStorage);
    }
    if (this.data.radioButton) {
      return this._saveRadioButton(evaluator, task, annotationStorage);
    }
    
    return null;
  }
  async _saveCheckbox(evaluator, task, annotationStorage) {
    if (!annotationStorage) {
      return null;
    }
    const storageEntry = annotationStorage.get(this.data.id);
    const value = storageEntry && storageEntry.value;
    if (value === undefined) {
      return null;
    }
    const defaultValue = this.data.fieldValue && this.data.fieldValue !== "Off";
    if (defaultValue === value) {
      return null;
    }