Incorrect parsing of Textbox in docx by OpenXML

Question

I am reading a .docx file using OpenXML in C#. It reads everything correctly but strangely, the content of textbox is being read thrice. What could be wrong? Here is the code to read .docx:

public static string TextFromWord(String file)
    {
        const string wordmlNamespace = "http://schemas.openxmlformats.org/wordprocessingml/2006/main";

        StringBuilder textBuilder = new StringBuilder();
        using (WordprocessingDocument wdDoc = WordprocessingDocument.Open(file, false))
        {
            // Manage namespaces to perform XPath queries.  
            NameTable nt = new NameTable();
            XmlNamespaceManager nsManager = new XmlNamespaceManager(nt);
            nsManager.AddNamespace("w", wordmlNamespace);

            // Get the document part from the package.  
            // Load the XML in the document part into an XmlDocument instance.  
            XmlDocument xdoc = new XmlDocument(nt);
            xdoc.Load(wdDoc.MainDocumentPart.GetStream());

            XmlNodeList paragraphNodes = xdoc.SelectNodes("//w:p", nsManager);
            foreach (XmlNode paragraphNode in paragraphNodes)
            {
                XmlNodeList textNodes = paragraphNode.SelectNodes(".//w:t", nsManager);
                foreach (System.Xml.XmlNode textNode in textNodes)
                {
                    textBuilder.Append(textNode.InnerText);
                }
                textBuilder.Append(Environment.NewLine);
            }

        }

        return textBuilder.ToString();
    }

The part of file I am talking about is:

The result is: I read it in a test application like this:

What's wrong here?