Another thing to check is that your relay reset clutches are working properly (reset motor is at D-5 on the schematic). I'm pretty sure the A/B/C/D beam trip relays are reset by one of the clutches engaging and allowing the reset cams to rotate. On Beam has two spring clutches on the reset bank shaft, allowing it to reset one half of the relay bank or the other, independently.
If the trip relays are never getting reset, the ship will stay on the same beam.
We had a good discussion about On Beam's reset mechanism a little while ago in this thread: https://pinside.com/pinball/forum/topic/bally-reset-bank-clutch-fix . I had some new clutch parts 3D printed, but the main problem is the spring inside. If the clutch binds from lack of lube (inevitable over time), it overwinds the clutch spring and ruins it. I have not been able to wind a replacement spring that works yet.

Hi, @WiXiS, didn't mean to leave your question hanging.
The reset motor should only turn once each time it's activated. Check the switches that are on the two bakelite discs on the reset camshaft. The switches are called #1 and #2 Reset Motor in the schematic. The motor should stop turning when the switch follower drops into the notch and the switch opens.
A switch on the Motor Trip Relay also can make the reset motor run, but I'm guessing it's one or both of the Reset Motor switches.

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OnBeamResetMotorCircuit.jpg