PG-FP5 free space will fill with FFH default, how to change config don't fill with FFH

dear sir or madam:

PG-FP5  free space will fill with FFH  default, how to change config don't fill with FFH, because of we meet a problem if fill with FFH, Using E1 debug program the MCU and not fill with FFH, no this kind of issue. thank you very much!