That may be your problem, but they look long enough to engage the square drive hole in the gearbox. Check to see if the jackshaft gearboxes can be turned. I had the gearboxes freeze on mine. The grease gets hard as it gets older. If they are stuck, you can try to clean and grease the gearboxes, and clean the jackscrews of rust, or you must replace the entire jackshaft assembly. If the jackscrews are rusty, that may be the issue. The jackshafts are synchronized for length, and if you move only one it will bind. They are held on at the back by a push nut on a pin, and at the front by two Allen screws, that also act as a pivot. If you remove both of them at the same time, the seat will flop around. I managed to get the push nut off without destroying it, and used it over again to install that end. I removed the Allen screws first, because the unit could not turn with the screw. I had to pull the seat cover back for access to the fasteners.
Make sure the jackshafts are protruding the same amount when you put it back together, or it will bind.
If only one is turning it will bind, and the motor will internally throw a breaker, or the breaker in the fuse block will activate.