Database function skipping data

public static List<string> RetrieveUserList()
{
  List<string> users = new List<string>();
  
  DBConnect.StartConnection(); // used to open connection with database
  
  try
  {
    using (DBConnect.Conn) // Use open connection
    {
      string getUsers = "SELECT userName FROM client_schedule.user"; // create command string
      
      using (MySqlCommand cmd = new MySqlCommand(getUsers, DBConnect.Conn))
      {
        MySqlDataReader reader = cmd.ExecuteReader();
        
        while (reader.Read())
        {
          string temp = reader.GetString(0);

          users.Add(temp);
        }
      }
    }
  }
  catch (MySqlExeception ex)
  {
    DBConnect.StopConnection(); // close if exception occurs

    MessageBox.Show(ex.Message);
  }
  
  DBConnect.StopConnection(); // close connection

  return users;
}