BQ30z55 Can read data flash, but cannot write data

My design is a 2 series protection circuit. After connecting the power, short B+, P+, the interface can be read as shown in the screenshot, but I cannot write the DATA FLASH parameter. The DATA FLASH parameter is always the initial value.

For example, I want to set Min Blow Fuse Voltage as  4200mV,but   in the screenshot,  You can see that it is still the original 8000mV and it turns red!

Why? Is there any restriction on writing? But SEC1, SEC0 are 0, 1 should be unlocked。