iPhone X mysterious tree-like crack on portrait Camera

I've just bought an iphone X and the camera has a mysterious crack on the screen when I view the portrait camera. The same image appears when I zoom in, but not consistently. It's very weird. For portrait it is always visible. There is no damage to the outside of the camera and I have had it in a Quadlock case since buying it and have not dropped it.

here is an example and a screen shot: