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)



pointsArray = [
        [
          { x: this.rectangle[0], y: this.rectangle[3] },
          { x: this.rectangle[2], y: this.rectangle[3] },
          { x: this.rectangle[0], y: this.rectangle[1] },
          { x: this.rectangle[2], y: this.rectangle[1] },
        ],
      ];
    }
    for (const points of pointsArray) {
      const [mX, MX, mY, MY] = pointsCallback(buffer, points);
      minX = Math.min(minX, mX);
      maxX = Math.max(maxX, MX);
      minY = Math.min(minY, mY);
      maxY = Math.max(maxY, MY);
    }
    buffer.push("Q");
    const formDict = new Dict(xref);
    const appearanceStreamDict = new Dict(xref);
    appearanceStreamDict.set("Subtype", Name.get("Form"));
    const appearanceStream = new StringStream(buffer.join(" "));
    appearanceStream.dict = appearanceStreamDict;
    formDict.set("Fm0", appearanceStream);
    const gsDict = new Dict(xref);
    if (blendMode) {
      gsDict.set("BM", Name.get(blendMode));
    }
    if (typeof strokeAlpha === "number") {
      gsDict.set("CA", strokeAlpha);
    }