when sitting in the truck seat (either seat) using the control panel to change the position of the ramp, stairs or blocks. Clicking on any of the enable button will either change the another item stat control. for example clicking on the 'right open stair' control and the 'ramp load' disable and 'ramp stow' enable. that just one but all control need to be check.
the movement of the Ramp, Stairs or blocks work for the most part excepted for the ramp going from full to load does not stow the length then drop down.
update: It look like to the Control panel part is fixed in (0.9.0249:39509) but one thing still is broken. And the that is the ramp going from the full ramp position to Load Position. It lift up and stop. It does not pull in the length of the ramp.