Word file used: 
[Formular_T.docx](https://github.com/mozilla/pdf.js/files/6907859/Formular_T.docx)

PDFs generated:
PDF 1: [Formular_T_default.pdf](https://github.com/mozilla/pdf.js/files/6907771/Formular_T_default.pdf)
PDF 2: [Formular_T_changed.pdf](https://github.com/mozilla/pdf.js/files/6907772/Formular_T_changed.pdf)

- PDF.js version: v2.9.359

Steps to reproduce the problem:
1. Create Word Document with Checkbox and check it.
2. Convert Word document to PDF using **Aspose.pdf** (for .net)

3. Extra: Change value of second Checkbox  in PDF 1 and save the file (PDF 2). The new File will show both Checkboxes checked in other browser, but only the newly checked one in PDF.js

Expected:
Checkbox is checked (pdf viewer from adobe/Chrome Version 92.0.4515.107 64-bit)
![image](https://user-images.githubusercontent.com/76941221/127659557-42be1cca-3c90-49b8-b224-70ee85aa1b30.png)

Result:
Checkbox is not checked (Mozilla Firefox/PDF.js)
![image](https://user-images.githubusercontent.com/76941221/127660064-e3cdc3f9-6887-4ae7-af27-d46cded69029.png)



pageIndex,
    };
    switch (subtype) {
      case "Link":
        return new LinkAnnotation(parameters);
      case "Text":
        return new TextAnnotation(parameters);
      case "Widget":
        let fieldType = getInheritableProperty({ dict, key: "FT" });
        fieldType = isName(fieldType) ? fieldType.name : null;
        switch (fieldType) {
          case "Tx":
            return new TextWidgetAnnotation(parameters);
          case "Btn":
            return new ButtonWidgetAnnotation(parameters);
          case "Ch":
            return new ChoiceWidgetAnnotation(parameters);
          case "Sig":
            return new SignatureWidgetAnnotation(parameters);
        }
        warn(
          `Unimplemented widget field type "${fieldType}", ` +
            "falling back to base field type."
        );
        return new WidgetAnnotation(parameters);
      case "Popup":
        return new PopupAnnotation(parameters);
      case "FreeText":
        return new FreeTextAnnotation(parameters);
      case "Line":