Yes, I hoped you would test it with the plastic knob. If you are able to easily move it by hand then either
a) Your stepper motors are not powerful enough for this machine and its losing steps when moving
b) Your current settings on the AIO board are not providing enough power to the motors so its losing steps when moving.
If your motors are nice and warm, like 30-50 degrees, then its issue A.
If they are not warm, its issue B). Dial up the current (small movements anticlockwise on the trim pots) then leave it to sit for a few minutes and check the temperature on the motors again.
They should be warm - cold stepper motors are not working hard. Steppers use allot of power sitting doing nothing, not moving just holding a position. If your machine is on for 5 minutes sitting holding position and not moving you would expect good warmth in the motors. Keep an eye on the driver warning LED’S on the AIO - you don’t want these coming on. Find a good balance between a good power to the motor and not overheating the drivers.
Also, watch the motor power as you dial up the drivers. You should notice small anti-clockwise adjustments make a big difference in how hard it is to overpower the machine by hand (using knobs).