BQ20Z75 - Change Security Keys 0x60 0x61

Hello,

I am struggling to change the security keys in BQ20Z75 using commands 0x60 and 0x61.

I recently posted asking the similar question with BQ40Z25 so you can see I am struggling with changing keys and probably writing to blocks.

So I am sending the following bytes to change the security keys

61 04 34 12 78 56

and then

60 04 CD AB FF FF

However that isn't changing the keys. Can anyone point out why this isn't working?