I have a function that it will detect the change of google sheet when anyone write something into google sheet. However,there is a problem. It cannot change the latest data if its value is 'O'. It still can send mail,but setValue() just didn't work on the latest data.

Does anyone know how to fix this problem? Here is my sheet data.

function sentMail(confirm) {
  var spreadsheet = SpreadsheetApp.openById('XXXXXXXX');
  var sheet = spreadsheet.getSheetByName('QAAZ');

  var mail = "xxx@gmail.com";
  var title = "test mail"

  var lastRow = sheet.getLastRow();
  var lastCol = sheet.getLastColumn();
  var range = sheet.getRange(1,1,lastRow,lastCol);
  var values = range.getValues();

  var rowCount = 2;
  var colCount = 14;
  
  Logger.log(values [rowCount][colCount - 1]);
  Logger.log(lastRow);
  lastRow = lastRow + 1;

  for(rowCount = 1; rowCount <= lastRow + 1; rowCount++){
    if(values [rowCount][colCount - 1] == 'O'){
      if(values [rowCount + 1][colCount -1] == 'O'){
        sheet.getRange(rowCount, colCount).setValue('V');
        sheet.getRange(rowCount + 1, colCount).setValue('V');
      }
      else{
        sheet.getRange(rowCount, colCount).setValue('V');
      }
      GmailApp.sendEmail(mail, title, "test");
      Logger.log(values [rowCount][colCount - 1]);
    }
  }

  

  
}