LTC6804-2 cannot be written

I'm designing a battery management system for automobiles. I use the chip LTC6804-2. I can read battery voltage, GPIO data and configuration data, but I can't write configuration data.
 
I also purchased the DEMO test board of LTC6804-2, including DC1942C, DC1941D and DC590B. When debugging with supporting software, I also encountered the same problem that I could not write configuration data.
 
Let me describe the specific software debugging situation:
1. I can read the configuration data "F0 00 00 00 00 00". 
2. There is default data "F8 00 00 00 00 00" in the input field of configuration data. First, I can't modify this data. Second, if I write this data, the configuration data I read is still "F0 00 00 00 00 00".