Lot From and To size not updating in BAPI_BOM_UPLOAD_SAVE

Hello All,

I am using BAPI_BOM_UPLOAD_SAVE for mass upload program of Production BOM but the problem is I am passing field values for MAST-LOSVN(From Lot Size) and MAST-LOSBS(To Lot Size) in Bapi however the corresponding fields are not updated.Inputs will be appreciated.