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)



constructor(params) {
    super(params);
    this._hasText = true;
    const dict = params.dict;
    
    if (!isString(this.data.fieldValue)) {
      this.data.fieldValue = "";
    }
    
    let alignment = getInheritableProperty({ dict, key: "Q" });
    if (!Number.isInteger(alignment) || alignment < 0 || alignment > 2) {
      alignment = null;
    }
    this.data.textAlignment = alignment;
    
    let maximumLength = getInheritableProperty({ dict, key: "MaxLen" });
    if (!Number.isInteger(maximumLength) || maximumLength < 0) {
      maximumLength = null;
    }
    this.data.maxLen = maximumLength;
    
    this.data.multiLine = this.hasFieldFlag(AnnotationFieldFlag.MULTILINE);
    this.data.comb =
      this.hasFieldFlag(AnnotationFieldFlag.COMB) &&
      !this.hasFieldFlag(AnnotationFieldFlag.MULTILINE) &&
      !this.hasFieldFlag(AnnotationFieldFlag.PASSWORD) &&
      !this.hasFieldFlag(AnnotationFieldFlag.FILESELECT) &&
      this.data.maxLen !== null;
  }
  _getCombAppearance(defaultAppearance, font, text, width, hPadding, vPadding) {