Attach (recommended) or Link to PDF file here: [form-cms1500.pdf](https://github.com/mozilla/pdf.js/files/5670936/form-cms1500.pdf) (Original opened in Acrobat and checked one radio-button)
Original Source: https://www.cigna.com/static/www-cigna-com/docs/health-care-providers/form-cms1500.pdf

Configuration:
- Web browser and its version: FF 83.0
- Operating system and its version: Win 10 Pro
- PDF.js version: 2.7.355

Steps to reproduce the problem:
1. Open the PDF here: https://mozilla.github.io/pdf.js/web/viewer.html
2. See that all radio-buttons are checked, which is wrong.

What is the expected behavior? (add screenshot)
![grafik](https://user-images.githubusercontent.com/12390057/101734698-f72d3900-3ac0-11eb-817e-94ce276797e8.png)

What went wrong? (add screenshot)
![grafik](https://user-images.githubusercontent.com/12390057/101734712-fc8a8380-3ac0-11eb-833d-412243a7950c.png)

This radio-button field can be found in object `45 0 obj`.
modificationDate.dataset.l10nArgs = JSON.stringify({
        date: dateObject.toLocaleDateString(),
        time: dateObject.toLocaleTimeString(),
      });
      popup.appendChild(modificationDate);
    }
    const contents = this._formatContents(this.contents);
    popup.appendChild(contents);
    if (!Array.isArray(this.trigger)) {
      this.trigger = [this.trigger];
    }
    
    this.trigger.forEach(element => {
      element.addEventListener("click", this._toggle.bind(this));
      element.addEventListener("mouseover", this._show.bind(this, false));
      element.addEventListener("mouseout", this._hide.bind(this, false));
    });
    popup.addEventListener("click", this._hide.bind(this, true));
    wrapper.appendChild(popup);
    return wrapper;
  }
  /**
   * Format the contents of the popup by adding newlines where necessary.
   *
   * @private
   * @param {string} contents
   * @memberof PopupElement
   * @returns {HTMLParagraphElement}
   */
  _formatContents(contents) {