[ARCORE] Stability problem with terrain detection.

I would like to be able to place objects on the ground thanks to ARCORE, and I encounter some stability concerns when it comes to leaving the area where the object finds and returning, the object moves, moves and no longer there or I have to drop it.

And secondly, there is a ditrance in height between the virtual floor and the real floor when I deposit an object. Someone would know the solution to this kind of trouble please?

Thank you for the attention to my request