Commit Problem with BAPI_SHIPMENT_CHANGE

Hi, all, thank you very much for your help.

I'm trying with <b>BAPI_SHIPMENT_CHANGE</b>, to change a shipment's Planning_Status. The Planning_Status is successfully updated. But, the LOCK of the shipment is NOT automatically released after the bapi commit.

Following is my detailed processing:

1. Write an ABAP LIST.

2. Press a button on the ABAP LIST's Application tool bar to call the bapi.

      AT USER-COMMAND.
         CASE sy-ucomm.
             WHEN 'CALL_BAPI'.
                  CALL FUNCTION 'BAPI_SHIPMENT_CHANGE'
                  ......
                  CALL FUNCTION 'BAPI_TRANSACTION_COMMIT'
                  ......
         ENDCASE.

3. After the bapi, stay at the current ABAP LIST wihout leaving.

Although I commit the bapi explicitly, and the planned update succeeds, the processing shipment <b>stays being locked</b> by me, <b>unless I leave the ABAP LIST</b>. And just when I leave the current screen, the lock is released.

I'm wondering, hasn't the BAPI_TRANSACTION_COMMIT committed successfully? Or, do I miss some steps?