Not able to uncheck automate PO order field in MM03 tcode through BAPI_MATERIAL_SAVEDATA

Hi all,

We are receiving an input file which consists of all the fields in MM01/MM02 tcode.

and we are passing all this data to the BAPI 'BAPI_MATERIAL_SAVEDATA' in my ABAP code.

there is checkbox in MM02 screen auto.po for which when i pass value as 'X' in imprt parameter table 'PLANTDATA' in BAPI it is getting reflected on MM02 screen. but when passing space to the same value the checkbox is not getting unchecked or updated

Kindly help me on this thanks.