Multiple sheet get updated if I make change in the first sheet.

public static void AddToWorksheetPart(WorksheetPart worksheetPart, WorkbookPart wbPart, DataTable data, int startRow)
       {

          // Stylesheet stylesheet = wbPart.WorkbookStylesPart.Stylesheet;

           // Get Worksheet object
           Worksheet worksheet = worksheetPart.Worksheet;

           // Get SheetData object for worksheet
           SheetData sheetData = worksheet.Descendants<SheetData>().FirstOrDefault();

           // Set starting row for adding data to template
           UInt32Value rowIndex = (UInt32Value)((UInt32)startRow);



           Row row1 = new Row()
           {
               RowIndex = rowIndex++,
               Spans = new ListValue<StringValue>() { InnerText = "1:3" },
               DyDescent = 0.25D
           };

           for (int columnIndex = 0; columnIndex < data.Columns.Count; columnIndex++)
           {
               Cell cell = new Cell() { CellReference = ColumnCaption.Instance.Get((Convert.ToInt32((UInt32)rowIndex) - 2), columnIndex) };
               CellValue cellValue = new CellValue();

               if (columnIndex == 0)
               {
                   cell.DataType = CellValues.String;
               }
               else
               {
                   cell.DataType = CellValues.Number;
               }

               cellValue.Text = data.Columns[columnIndex].ColumnName.ToString().FormatCode();
               cell.Append(cellValue);

               row1.Append(cell);
           }
           sheetData.Append(row1);


           // Iterate through rows of DataTable
           for (int rIndex = 0; rIndex < data.Rows.Count; rIndex++)
           {
               // Create Open XML row object
               Row row = new Row()
               {
                   RowIndex = rowIndex++,
                   Spans = new ListValue<StringValue>() { InnerText = "1:3" },
                   DyDescent = 0.25D
               };

               // Iterate through columns of DataTable
               for (int cIndex = 0; cIndex < data.Columns.Count; cIndex++)
               {
                   if (cIndex == 0)
                   {
                       // Add new cell to the Row object
                       Cell cell = new Cell()
                       {
                           CellReference = ColumnCaption.Instance.Get((Convert.ToInt32((UInt32)rowIndex) - 2), cIndex),
                           DataType = CellValues.String

                       };

                       // Set value to Cell object from DataTable[Row][Column] using CellValue type
                       CellValue cellValue = new CellValue();
                       if (!String.IsNullOrEmpty(data.Rows[rIndex][cIndex].ToString()))
                           cellValue.Text = data.Rows[rIndex][cIndex].ToString();
                       else
                           cellValue.Text = "NULL";

                       cell.Append(cellValue);

                       row.Append(cell);

                   }
                   else
                   {
                       // Add new cell to the Row object
                       Cell cell = new Cell()
                       {
                           CellReference = ColumnCaption.Instance.Get((Convert.ToInt32((UInt32)rowIndex) - 2), cIndex),
                           DataType = CellValues.Number

                       };

                       // Set value to Cell object from DataTable[Row][Column] using CellValue type
                       CellValue cellValue = new CellValue();
                       // cellValue.Text = data.Rows[rIndex][cIndex].ToString();
                       if (!String.IsNullOrEmpty(data.Rows[rIndex][cIndex].ToString()))
                           cellValue.Text = data.Rows[rIndex][cIndex].ToString();
                       else
                           cellValue.Text = "NULL";
                       cell.Append(cellValue);
                       row.Append(cell);
                   }
               }
               // Add Row object to SheetData and Worksheet
               sheetData.Append(row);
           }
       }

public static void AddToExcelParts_Inter(SpreadsheetDocument spreadsheetDoc, DataTable data, int startRow, string sheetName)

 {
     // Get WorkbookPart object for document
     WorkbookPart workbookPart = spreadsheetDoc.WorkbookPart;
     WorksheetPart worksheetPart = GetWorksheetFromSheetName(workbookPart, sheetName);
     // Call method to insert data
      AddToWorksheetPart(workbookPart.WorksheetParts.ElementAt(0),workbookPart, data, startRow);

     // Save the WorkbookPart and document
      workbookPart.Workbook.Save();
 }