These are the circuits that hold the Bonus Score relay energized. Check these switches/units. Does the Bonus unit make it all the way to its zero position?

pasted_image (resized).png

The wiper fingers on the disk in the Bonus unit. That's the part I was asking about in my question.

You can tell what position the Bonus Unit is in by looking at the bonus lights on the playfield.

Also, it would be very unusual for a working bonus unit to reset quickly to zero (like in your video). Normally they count down 1 for each activation of the Bonus Unit Reset solenoid.

I have no idea what your latest picture is showing.
Maybe another Nip It owner can tell us whether their Bonus unit counts down one-at-a-time or all-at-once.
I'm pretty sure your Bonus unit is put together incorrectly.