Problems with choo choo/catapult mechanism

So I’ve recently tried making a choo choo/catapult mechanism and for some reason once the stopper/peg hits the arm it just stops instead of pushing it down. Here are some images

Are you able to make ti go through the motions by hand? With minimal banding? The gear ratio is more for speed than power, and you may need the motor to push a 12 tooth gear into the 60 tooth gear.

I’m able to move it by hand but once the stopper touches the arm it just stops and doesn’t move any more.

It will be pretty hard to troubleshoot, even with a video. Keep looking around the mechanism to see where it is hitting as you are turning it. Make sure that the shafts aren’t sticking out into the middle of the space in the middle as well.