xls created through C #, but does not add values

I have a method that generates excel (.xls), but I have a problem: excel is being generated perfectly, but when I try to sum the values of the cells nothing happens, it only adds if I open cell by cell (I do not need change any value).

In the image below you have an example, all values are aligned to the left but when I click on the cell to edit they automatically align to the right and it becomes possible to add them.

ThosethathaveareddashcanbeaddedbecauseIalreadyclickedonthecellasifitweretoedititsvalue.AndtheothervaluesarenotpossibletoaddbecauseIdidnotclicktoeditthemonce.

Thecodethatformatsthecellsisthis:

if(gradeColuna!=null)switch(gradeColuna.type){case"string": excelRange.NumberFormat = "@"; break;
                        case "date": excelRange.NumberFormat = "dd/mm/aaaa"; break;
                        case "datetime": excelRange.NumberFormat = "dd/mm/aaaa hh:mm;@"; break;
                        case "double": excelRange.NumberFormat = "#.##0,00#"; break;
                    }
                else
                    excelRange.NumberFormat = "@";

And what assigns the values is this:

foreach (DataRow dr in dados.Rows)
        {
            for (int i = 1; i < dados.Columns.Count; i++)
            {
                xlWorkSheet.Cells[linha, i] = dr[i].ToString()
                                                   .Replace("01/01/1900  00:00:00", "")
                                                   .Replace("00:00:00", "")
                                                   .Replace("01/01/1900", "")
                                                   .Trim()
                                                   .Replace("\n", Environment.NewLine);

                if (dr[i].ToString().Contains("\n"))
                    xlWorkSheet.Range[xlWorkSheet.Cells[linha, i], xlWorkSheet.Cells[linha, i]].WrapText = true;

                if (dr[i].ToString().Length >= 100)
                    xlWorkSheet.Columns[i].ColumnWidth = 100;

                decimal valorTemp = 0M;
                if (decimal.TryParse(dr[i].ToString(), out valorTemp))
                {
                    var teste = xlWorkSheet.Cells[linha, i];
                    if (dados.Columns[i].DataType.Name == "Decimal" || dados.Columns[i].DataType.Name == "Double")
                        xlWorkSheet.Cells[linha, i].Value = valorTemp.ToString("N2");
                }
            }

            linha++;
        }

        xlWorkSheet.Columns.AutoFit();
        xlWorkSheet.Rows.AutoFit();

If you have any doubts or anything badly explained, please ask me.

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