New Mi6 Navigation Button Change Missing

[Trytogetme]

Hi There. With the newest rom I am not able to change my navigation buttons under the screen.
I preffer LEFT -> Go Back and RIGHT->Taskmanager. I changed this when I get the device. But with newews Update (7.9.7 beta) the settings changed back, and the option is missing in settings.
Can you please bring that back?

 

[fpdesign]

I have the same issue