Shooting a cannonball (Projectile) doesn't work - C++

I’ve tried some things and looked on Velocity and Initial Speed. The Initial Speed was set to 3000 so this was fine. But the Velocity was set to (1/0/0) and and I want to shoot in Y direction so I’ve changed it to (0/1/0). I’ve also set simulate physics only for the root.

Now at least the cannonball gets an impulse and does SOMETHING. When I shoot, it spawns, gets an impulse but doesn’t fly in Y or -Y it starts to do somersaults and changes its direction every second. The other things is after ~5 shots the moventment behavior changes and it just drops in the wrong Y direction with a minimal speed.

Movement for the first ~5 shots:

Movement after the ~5 shots: