Quoted from FLASHBALL:
Anyone have an issue with their cannon shot being too powerful? Mine seems to want to bounce out of the broadside shot even on a direct shot. There is a gate on it but I think the ball is bouncing back before the gate can come down.
The spring is probably missing from your gate.
https://pinside.com/pinball/forum/topic/black-rose-club-owners-and-fans-welcome/page/28#post-5814012