Quoted from PokerJake:

Is there a bug where you can't start the race when you hit the skill shot on ball one? The magnet catches it but the race doesn't start for the rest of ball one. I had that happen for crash loop mb as well, magnet would catch but wouldn't start the mode. I hit the left orbit at least 4 times, but the next ball it started when I hit the orbit.

Quoted from Ferret:

Try going into Tests > Switch, and roll a ball up the left orbit -- preferably several attempts at various speeds... make sure that BOTH "Left Orbit Enter" and "Left Orbit Made" get triggered consistently. If either one sometimes doesn't register, it could result in the symptom you describe... in which case, a little adjustment of the errant switch should hopefully fix things up.