Trigger does not Fire with ASP.Net SqlBulkCopy using VB.Net

Hi, I hope you have a nice day, i have a problem with my code, i am trying to make my triggers works, this is my code os vb:

 Dim conn As String = ConfigurationManager.ConnectionStrings("REPP2018").ToString()
            Dim conexion As New SqlConnection(conn)
            conexion.Open()

            Dim copy As New SqlBulkCopy(conn, SqlBulkCopyOptions.FireTriggers)
            copy.DestinationTableName = "dbo.DETALLE_ASISTENCIA"

            copy.ColumnMappings.Add("ID_ASISTENCIA", "ID_ASISTENCIA")
            copy.ColumnMappings.Add("Clavep", "Clavep")
            copy.ColumnMappings.Add("REGISTRO", "REGISTRO")
            copy.ColumnMappings.Add("PROPIETARIO", "PROPIETARIO")
            copy.ColumnMappings.Add("SUPLENTE", "SUPLENTE")
            copy.ColumnMappings.Add("AMBOS", "AMBOS")
            copy.ColumnMappings.Add("NINGUNO", "NINGUNO")
            copy.ColumnMappings.Add("JUSTIFICACION", "JUSTIFICACION")

            copy.WriteToServer(DS)

            conexion.Close()

the data is inserting ok, and this is my code of the trigger :

ALTER TRIGGER  [dbo].[DETECTA_FALTAS]
   ON  [dbo].[DETALLE_ASISTENCIA]
AFTER INSERT,UPDATE
AS 
BEGIN
DECLARE @REGISTRO BIT,@NINGUNO BIT, @JUSTIFICACION BIT,@DTTO INT,@MPIO INT,@CONSEJO CHAR(3),@Clavep INT,@da int

DECLARE @cur CURSOR
SET @cur = CURSOR FOR SELECT i.REGISTRO,i.NINGUNO,i.JUSTIFICACION,i.ID_DETALLE_ASISTENCIA FROM inserted i
OPEN @cur
FETCH NEXT FROM @cur INTO @REGISTRO,@NINGUNO, @JUSTIFICACION,@da
WHILE @@FETCH_STATUS = 0
BEGIN

	SELECT @DTTO=ASISTENCIA_REGISTROS.ID_DISTRITO,@MPIO=ASISTENCIA_REGISTROS.ID_MUNICIPIO,@CONSEJO=ASISTENCIA_REGISTROS.CONSEJO,@Clavep=ASISTENCIA_REGISTROS.Clavep
	FROM ASISTENCIA_REGISTROS JOIN DETALLE_ASISTENCIA 
	ON DETALLE_ASISTENCIA.ID_ASISTENCIA=ASISTENCIA_REGISTROS.ID_ASISTENCIA AND DETALLE_ASISTENCIA.ID_DETALLE_ASISTENCIA=@da
	
	IF (@REGISTRO='True' and @NINGUNO='True' and @JUSTIFICACION='False' )
	print @CONSEJO
	EXEC GENERA_FALTAS @DTTO,@MPIO,@CONSEJO,@Clavep
    -- Insert statements for trigger here
   -- SELECT INSERTED.Clavep,CONSEJO,ID_DISTRITO,ID_MUNICIPIO FROM ASISTENCIA_REGISTROS JOIN INSERTED ON INSERTED.ID_ASISTENCIA=ASISTENCIA_REGISTROS.ID_ASISTENCIA AND INSERTED.ID_DETALLE_ASISTENCIA=ASISTENCIA_REGISTROS.ID_DETALLE_ASISTENCIA

    FETCH NEXT FROM @cur INTO @REGISTRO,@NINGUNO, @JUSTIFICACION,@da  --fetch next record
END
END

when i insert some data from sql server the triggers is working fine, but from my application it doesn't work

I apreciate any help, thanks.