Simulate ball bearing in tube with gravity

Hey all, I'm a noob at simulation & motion studies, and I'm trying to learn with a simple set-up (at least, I think it's simple). I've got a ball and a bent tube (see attachment), and I want to show the ball travelling down the tube under gravity alone. I've got gravity turned on and contact setup between my ball and my tube; but when I run the simulation, the ball travels down the initial incline (accelerating as it should under gravity), but when it gets to the bend to run straight horizontally, the ball actually passes through the tube and then drops out of sight. It's like only the initial inclined portion of the tube exists. It's seems like the contact fails as it gets to the bend. Any ideas? Thanks!

SolidworksSimulation