Hi 5280wzrd
I once made an JPG to talk about "at end of a ball: HOW are given 'maybe 1000 points - the violet 1' - 'maybe 2000 points - the violet 1,2' - maybe 3000 points - the violet 1,2,3' etc.".
In every position of the I-Bonus-Unit the motor makes a turn, the Motor-Switch-1A always fires five pulses --- but switches motor-2C, -3B, -1B, -4C open and do not allow all five shots to pass. See the "violet stuff".
To create the fault in Your pin: I say "Switches in the G-Relay are faulty closed (encircled thick orange)" --- the "switches encircled dashed orange - the Joker-Switches are entitled to be closed" --- along my orange wiring: The opening of motor-2C, -3B are bypassed --- fired pulses (motor-1A) can pass along the orange lines.
I suggest: Inspect the the G-Relay - faulty pulling ? --- inspect the switches on the G-Relay -faulty closed when the relay is not pulling ? Greetings Rolf