If everything goes up and down easily, but you have intermittent issues with the motor, it could very possibly be the control board which is under the main platform. Check for loose wires under there.
Contact B9 Support and they may be able to help diagnose the board or how to check it.
I have replaced my board on the 1.1 2 times. The board seems to get damaged when the table/ Platform gets stuck and keeps trying to release from the pdms. eventually that can damage the board