Tracking issues, elements don't keep the initial spot were placed

Hi All!

Hope you are all ok, and safe.

I was doing a demo, for a simple AR 3D model Log with a Video.
I’m having BIG problems with the tracking.
The elements do not keep the spot I place them, and they start to move slightly all the time.
I tested the beta.zappar.app with the instant tracking and it also moves, and does not keep the initial place.
Every other single AR MR app I have and tested does not do this.
Samsung S10 and iPad Pro 2020.