Thank you Michael.

Ralf3 pointed out that the star is embedded in the (keyshot) ground plane.

"I want to give you a hint: Your star is "dipped" in the ground plane.
You can change it easy, with "Snap to ground.
Options -> Scene -> At the bottom -> Snap to ground. (In Keyshot2 program.)
Your star is now above the ground plane"
Thanks again Ralf3!