Looking for help as I am completely lost.

Long story short, my Slugfest arm broke off the motor rod. I replaced the pitch assembly from Marco.
Everything was installed according to the manual - arm facing front of cabinet with opto UNBLOCKED.

Game pitches but the arm spins around 2x and stops in random places. So it basically "double pitches." It never stops (or resets) in the same place consistently.
I did a switch test and the optos seems to work. I can't find anywhere if there is a switch that stops the arm from moving??

Can a Slugfest owner, or whomever has worked on this game chime in to let me know what the proper movement of the arm mech should be? I haven't even played a full game on this so I don't know exactly what it is suppose to do. Thanks for any and all input here.

Can any owners help here?