Quoted from dscapo:I’ll try this when I get home. I guess I was assuming that it was working because everything functions fine in single ball play and when two balls are in play during the multiball.
Quench is almost certainly correct. There are two switches over there, the one he circled is the one that actually triggers the release, not the ramp entry switch that triggers the audio cue, it was done this way to that a partial shot that rolls back down the ramp won't create an un-earned multiball. The reason it works properly when a ball isn't locked is that there is another switch in the actual eject hole that tells a game the ball is there so it can still kick it out when it should in single ball play but won't when one is locked.