Chicago Coin Preview Ball Bowler Issues

I have a Preview ball bowler and it recently started some strange behavior. It seems like on random frames after the pin reset it will make a quick buzzer sound and a few of the pins will go up. Usually it's the 1 and 5 pin but I've seen a few other sets. We played a 4 player round today and I would say it happend on about 5 or so frames. You can still bowl the frame but it's impossible to get a strike or spare.

I know nothing about EM's so any info on this or any suggestions would be really appreciated.

Thanks.