Question AR foundation 4.0 update position

Hi everybody,

I am using a 3d Map scaled with the real dimension of my flat. I would like the position of my placeholder on the 3d map while I am moving around in the real environment. The effect that I would like to have is to have the map visible behind me with my position updated while I am moving

I added an AR Pose driver on the AR Camera and seem working pretty fine but I would like to remove the update of the Y to avoid the drifting of the map behind me.

Could anyone explain to me if the approach is right? Do I need to set up a plane recognition and update the position directly with the ScreenToviewport functionality?

Thank you for any advice in advance