Filter Issue in ALV Grid

I am displaying the table in ALV Grid format. I have 4 fields in the table. The filter works for the first 3 fields, but doesnot work for the last field.

Please let me know what might be the issue.

Find the table declaration and the table population as in the below code

TYPES : BEGIN OF ty_message,
          avm_nr  TYPE avm_nr,
          motiv   TYPE motiv_nr,
          text    TYPE t100-text,
          msg     TYPE merep_orderstat,
        END OF ty_message.

DATA: gt_message TYPE STANDARD TABLE OF ty_message,
          gs_message TYPE ty_message.


    gs_message-avm_nr   = gs_upload-avm_nr.
    gs_message-motiv      = gs_upload-motiv.
    gs_message-text        = 'Order Successfully Changed'.
    gs_message-msg       = 'Success'.

    APPEND gs_message TO gt_message.
    CLEAR gs_message.

Regards,

Salil