Getting no idea where i am going wrong, my IT_MSEG is fetching data, but when modifying IT_FINAL, the values are not getting transported. Need help, please point where i am going wrong.

Thanks.

REPORT ZROQ_STATUS_REPORT.

TABLES: MARA , MARC , MSEG.

TYPE-POOLS: SLIS.

TYPES: BEGIN OF TY_FINAL,
 MATERIAL_NO TYPE MARA-MATNR, 
 MATERIAL_GRP TYPE MARA-MATKL, 
 MATERIAL_NO2 TYPE MARC-MATNR, 
 PLANT TYPE MARC-WERKS, 
 MVMT_TYP TYPE MSEG-BWART,
 MTRL_DOC_NO TYPE MSEG-MBLNR,
 QUANTITY TYPE MSEG-MENGE,
 BATCH_NO1 TYPE MSEG-CHARG,
 BATCH_NO2 TYPE MSEG-CHARG,

END OF TY_FINAL.

DATA: IT_FINAL TYPE TABLE OF TY_FINAL,
 WA_FINAL TYPE TY_FINAL.


 SELECTION-SCREEN BEGIN OF BLOCK BK1 WITH FRAME TITLE TEXT-001.
 SELECT-OPTIONS: SO_MTART FOR MARA-MTART.
 SELECT-OPTIONS: SO_MATKL FOR MARA-MATKL.
 SELECTION-SCREEN END OF BLOCK BK1.


 SELECTION-SCREEN BEGIN OF BLOCK BK3 WITH FRAME TITLE TEXT-003.
 SELECT-OPTIONS: SO_DATE FOR MSEG-BUDAT_MKPF.
 SELECT-OPTIONS: SO_WERKS FOR MARC-WERKS.
 SELECTION-SCREEN END OF BLOCK BK3.

START-OF-SELECTION.
 PERFORM GET_DATA.


 FORM GET_DATA.

* MARA
 SELECT MATNR,
 MATKL
 FROM MARA
 INTO TABLE @DATA(IT_MARA)
 WHERE MATKL IN @SO_MATKL AND MATKL IN ( 'FG01' , 'FG02' ). "matkl = 'FG01' & 'FG02'.

LOOP AT IT_MARA INTO DATA(WA_MARA).
 WA_FINAL-MATERIAL_NO = WA_MARA-MATNR.
 WA_FINAL-MATERIAL_GRP = WA_MARA-MATKL.
 APPEND WA_FINAL TO IT_FINAL.
 CLEAR: WA_MARA , WA_FINAL.
 ENDLOOP.

* MARC
 IF IT_FINAL[] IS NOT INITIAL.
 SELECT MATNR,
 WERKS
 FROM MARC
 INTO TABLE @DATA(IT_MARC)
 FOR ALL ENTRIES IN @IT_FINAL
 WHERE MATNR = @IT_FINAL-MATERIAL_NO AND WERKS IN @SO_WERKS AND WERKS IN ( 'PM01' , 'PM02' ).
 ENDIF.

LOOP AT IT_FINAL INTO WA_FINAL.
 READ TABLE IT_MARC INTO DATA(WA_MARC) WITH KEY MATNR = WA_FINAL-MATERIAL_NO.
 IF SY-SUBRC = 0.
 WA_FINAL-MATERIAL_NO2 = WA_MARC-MATNR.
 WA_FINAL-PLANT = WA_MARC-WERKS.
 MODIFY IT_FINAL FROM WA_FINAL TRANSPORTING MATERIAL_NO2 PLANT.
 CLEAR: WA_MARC , WA_FINAL.
 ENDIF.
 ENDLOOP.

* MSEG
 IF IT_FINAL[] IS NOT INITIAL.
 SELECT MATNR,
 WERKS,
 BUDAT_MKPF, 
 BWART, 
 MBLNR, 
 MENGE, 
 CHARG 
 FROM MSEG
 INTO TABLE @DATA(IT_MSEG)
 FOR ALL ENTRIES IN @IT_FINAL
 WHERE MATNR = @IT_FINAL-MATERIAL_NO2
 AND WERKS = @IT_FINAL-PLANT
 AND BUDAT_MKPF IN @SO_DATE
 AND BWART = '101'.
 ENDIF.

* Values are getting stored in IT_MSEG but when trying to modify IT_FINAL, the values are not getting transported.
 LOOP AT IT_FINAL INTO WA_FINAL.
 READ TABLE IT_MSEG INTO DATA(WA_MSEG) WITH KEY MATNR = WA_FINAL-MATERIAL_NO2
 WERKS = WA_FINAL-PLANT
 BUDAT_MKPF = SO_DATE
 BWART = '101'.


 IF SY-SUBRC = 0.
 WA_FINAL-MVMT_TYP = WA_MSEG-BWART.
 WA_FINAL-MTRL_DOC_NO = WA_MSEG-MBLNR.
 WA_FINAL-QUANTITY = WA_MSEG-MENGE.
 WA_FINAL-BATCH_NO1 = WA_MSEG-CHARG.
 MODIFY IT_FINAL FROM WA_FINAL TRANSPORTING MVMT_TYP MTRL_DOC_NO QUANTITY BATCH_NO1.
 CLEAR: WA_FINAL , WA_MSEG.
 ENDIF.
 ENDLOOP.