Jittering, changing location and size of the model in VPS Camera view

I have setup a VPS Aframe project as per the tutorial and added a turtle 3d model to it. But it seems that when I try to view the camera view, after multiple tries I do get the turtle in view. But it may move to a different location, it may change its size or it may sometimes even fly away. I have set the scale rotation and position properly as per the tutorials. But it seems that maybe I missed something that can fix the 3d model in a specific place in relation with the 3d model of the scan. Kindly help regarding this and do let me know what information is required.

This could be related to a few different things. Can you share the project with the support workspace?