Function Module WS_DELIVERY_UPDATE_2 not updateing Picking/putaway confirmation

Hi Experts,

I'm using FM 'WS_DELIVERY_UPDATE_2' to process picking on a modbile scanner.

Everything is working well except the "Picking/Putaway confirmation (LEDLVSTATDISPITEM-KOQUA)' Status is not getting updated and remains on 'B'.

My Code:

wa_vbkok-vbeln_vl = zsdmob_in01m-vbeln.      "outbound delivery no
wa_vbkok-vbtyp_vl = 'J'.
wa_vbkok-kodat = sy-datum.
wa_vbkok-kouhr = sy-uzeit.
wa_vbkok-kzpod = 'V'.

* update picking for line item
  CALL FUNCTION 'WS_DELIVERY_UPDATE_2'
    EXPORTING
      vbkok_wa                           = wa_vbkok
      COMMIT                             = 'X'
      delivery                           = zsdmob_in01m-vbeln
      update_picking                     = 'X'
      SYNCHRON                           = 'X'
   IMPORTING
     ef_error_any                       = wa_error
     ef_error_in_item_deletion          = w_error_in_item_deletion
     ef_error_in_pod_update             = w_error_in_pod_update
     ef_error_in_interface              = w_error_in_interface
     ef_error_in_goods_issue            = w_error_in_goods_issue
     ef_error_in_final_check            = w_error_in_final_check
     ef_error_partner_update            = w_error_partner_update
     ef_error_sernr_update              = w_error_sernr_update
   TABLES
     vbpok_tab                          = t_vbpok.

When I want to do Processes Goods Issue I get the Error "Picking request not yet confirmed".

Please avdise on any help to get  this sorted.

Regards

Ian