Quoted from Jmckune:
Do you not have a diverter? That would have had to fire if you were going to get a 3rd ball in the lock and if it fired it didn’t know there was a second ball there
Yeah - the game plays flawless. I have played 1000+ games without any strange issues. This is a really unique set-up though that will probably never happen again. You are correct about the diverter though - it would have had to fire for the ball to go in the lock.
That is why I think a software weakness could be at play. The ball passes the first switch on the ramp and I get awarded a compass point, thereby triggering a set-up for a lock (raising the ramp because there are already two balls in there from the other player). Maybe it threw the diverter in a sequence of events error (knowing the ball is coming and a lock shot has been awarded and the ramp is still in the down position).
I am going to pull the glass and verify the third switch activates with three balls sitting there. That will only explain the searching for a ball routine though.