Summary of bug here:
On Sweet Tooth Hole 1, either the mint colored ice cream scoop, or the guide rail right after the first turn has incorrect collision, causing your ball to fly off in random directions.
Steps to Reproduce
Start a fresh game, and hit your ball into the small curve right off of the starting point. This should shoot the ball into the outer boost pad, and into position right before the hill. Hit the ball as if you are about to skip over the guide rail next to the mint scoop.
See notes below for a consistent setup video.
What I expected to happen
The ball to skip gracefully over the guide rail, and into the second turn.
What happened
The ball bounced off of incorrect collision.
Notes / Media
Youtube video link: