Just got my game, was very excited as I didn't have any plunger/auto plunge issues with my game. Installed the amber shooter rod, and now my plunges/auto plunges are failing over all over the place.
Adjusted my ramp, added a washer, removed a washer, nothing seemed to fix the issue. (My game was an August build, it doesn't need the washer. Even though it "looks" a little off, using your finger you can check the alignment of the ramp, washer actually made mine worse.
Happened to look at how the plunger sits on the ball, and its off center by a lot! Shouldn't matter for the auto plunge right? Well the ball sits back on the plunger for a split second during auto plunge, and if its off, it will mess up the auto plunger.
I haven't tried to fix my plunger alignment yet, going to tackle that tomorrow, but just an FYI, check your leveling, and then check your plunger tip to make sure its centered to the ball!