RSNAST0D: printing a message by z-program problem

To print by message, I tried to use directly the CALL FUNCTION (WFMC_MESSAGES_SELECT, WFMC_MESSAGES_PROCESS, ...) but it didn't work.

So I'm trying to use the standard program RSNAST0D.

If I call it by SE38, it works fine with my example. If I call by my z-program it doesn't work.

If I stop the program in debug at the first instruction (CALL FUNCTION 'WFMC_MESSAGES_SELECT') in two sessions with both the two cases (called directly by SE38 and called by my z-program) I can see the same parameters values in both sessions.

But only one of them gets the spool.

This is the code of the SUBMIT, but I think it is not important: I'm sure that the parameters values are identical, as it was called directly:

    wa_selection-selname = 'S_KAPPL'.
    wa_selection-kind    = 'S'.
    wa_selection-sign    = 'I'.
    wa_selection-option  = 'EQ'.
    wa_selection-low     = 'V2'.
    APPEND wa_selection TO it_selection.
    wa_selection-selname = 'S_NACHA'.
    wa_selection-kind    = 'S'.
    wa_selection-sign    = 'I'.
    wa_selection-option  = 'EQ'.
    wa_selection-low     = '1'.
    APPEND wa_selection TO it_selection.
    wa_selection-selname = 'S_KSCHL'.
    wa_selection-kind    = 'S'.
    wa_selection-sign    = 'I'.
    wa_selection-option  = 'EQ'.
    IF f_type = 'PKL'.
      wa_selection-low =  'ZLD2'.
    ELSEIF f_type = 'RIR'.
      wa_selection-low =  'ZRIR'.
    ELSEIF f_type = 'RID'.
      wa_selection-low =  'ZRID'.
    ELSEIF f_type = 'DDT'.
      wa_selection-low =  'ZLDF'.
    ENDIF.
    APPEND wa_selection TO it_selection.
    wa_selection-selname = 'S_OBJKY'.
    wa_selection-kind    = 'S'.
    wa_selection-sign    = 'I'.
    wa_selection-option  = 'EQ'.
    wa_selection-low     = wa_zmspool-vbeln.
    APPEND wa_selection TO it_selection.
    wa_selection-selname = 'P_MODE'.
    wa_selection-kind    = 'P'.
    wa_selection-option  = 'EQ'.
    wa_selection-low     = f_vermo.
    APPEND wa_selection TO it_selection.
    wa_selection-selname = 'P_DIALOG'.
    wa_selection-kind    = 'P'.
    wa_selection-option  = 'EQ'.
    wa_selection-low     = ' '.
    APPEND wa_selection TO it_selection.
    wa_selection-selname = 'P_GRID'.
    wa_selection-kind    = 'P'.
    wa_selection-option  = 'EQ'.
    wa_selection-low     = ' '.
    APPEND wa_selection TO it_selection.

   SUBMIT RSNAST0D WITH SELECTION-TABLE it_selection AND RETURN.