Quoted from Kawydud:The more I was thinking about it last night, I don't think it was the eject power. I was popping the balls out manually with the coil plunger. Doing this manually was still popping the two balls out, but only when they weren't lined up in the trough properly. Meaning they were pushed in just a touch too much, making ball number one up in the air a little bit.
Is one ball sticking to another because they are magnetized? Switch out the balls and try.