Adding physicsImposter does odd behavior

[Pryme8]

So I have a scene where I am building the colliers for the scene after the visual meshes are constructed.  I have been trying to get this code to work:
 

if(this.assets['Ground-Body-0'].physicsImposter){
				this.assets['Ground-Body-0'].physicsImposter.dispose()
			}
			this.assets['Ground-Body-0'].scaling.z = (Math.ceil(level/5)+1)*this.scale*12
			this.assets['Ground-Body-0'].position.z = Math.ceil(level/5)*12			
			this.assets['Ground-Body-0'].renderingGroupId = 2
			
			var wallColliders = []
		
			wallColliders.push(this.assets['Ground-Body-0'].clone('Wall-Body-0'))
			wallColliders[0].position.x =  -this.scale*6
			wallColliders[0].setPivotPoint(new BABYLON.Vector3(this.scale*3, 0, 0))			
			wallColliders[0].rotation.z =  -Math.PI*0.2
			
			wallColliders.push(this.assets['Ground-Body-0'].clone('Wall-Body-1'))
			wallColliders[1].position.x =  this.scale*6
			wallColliders[1].setPivotPoint(new BABYLON.Vector3(-this.scale*3, 0, 0))			
			wallColliders[1].rotation.z =  Math.PI*0.2
			
			this.assets['Ground-Body-0'].physicsImposter =  
			new BABYLON.PhysicsImpostor(this.assets['Ground-Body-0'], BABYLON.PhysicsImpostor.BoxImpostor, { mass: 0, restitution: 0.3 },  this.scene)
			
			//wallColliders[0].physicsImposter =  
			//new BABYLON.PhysicsImpostor(wallColliders[0], BABYLON.PhysicsImpostor.BoxImpostor, { mass: 0, restitution: 0.3 },  this.scene)
			
			//wallColliders[1].physicsImposter =  
			//new BABYLON.PhysicsImpostor(wallColliders[1], BABYLON.PhysicsImpostor.BoxImpostor, { mass: 0, restitution: 0.3 },  this.scene)

What I am noticing, is when I add the physics imposter to the "wall" it disappears.  Alternatively if I create the imposter first and then clone the "ground" mesh, I get the same results of the walls disappearing.   

Ive tried making it unique geometry, backing the transform etc... and am kinda stumped.

Pretty sure its linked to the set PivotPoint, but I was just wondering if anyone had any input on to what would cause behavior like this.

[Guest]

Pretty sure it comes from the pivot as well. How does it look like without the lines about pivot?

Pinging @RaananW for review if he is around

[Pryme8]

Yup stripping the pivot position fixes it going ghost on me... but I need to be able to rotate by a pivot position so I guess put it into a transform container and manipulate that?

[dbawel]

Parenting to a bounding/parent mesh which can act as the collider? Sometimes you overthink these things - I know....

DB

[RaananW]

When you miscalculated a position or any of the joint's values (or, well, whenever I make a mistake developing the physcis plugins), there is a chance the physics engine will react rather aggressively and will throw the body "somewhere" in a single frame. 

If you can reproduce this in the plyground I will be able to help with finding what went wrong