Random Clipping Through Mesh

I have created a test scene in which a sphere that is set to roll over a mesh occasionally clips through the mesh. This appears to be random, in the video you can see it doesn't clip the first time, then clips the next few times and finally doesn't clip the final time.

I'm not sure why the behaviour would be inconsistent across multiple attempts, I was under the impression that ECS physics was supposed to be deterministic.

Also, possibly unrelated but in the final attempt the ball starts listing to the left when the initial velocity should have it continuing straight since the part of the mesh it's travelling on is flat. You can also sort of see it bouncing when it gets to the internal mesh edges.

Unity version: 2019.3.0b2
Unity Physics version: 0.2.2