BQ28Z610: changing the DesignCapacity parameter

Part Number:BQ28Z610

Team, 

we are unable to change the default setting of DesignCapacity=4400 to our custom value - the save of the new value fails. 

According to the documentation the device needs to be in US / FA setting and in SE the device can only read.

For Security Mode SE1,SE0 bits we see '0'.

Can you advise how to change the DesignCapacity?

Thanks for your help,
TI Customer