The actuator looks fine. The seat seems to be hitting the rail end stop, those black slider blocks before the actuator finishes its stroke.
Can you prop the seat, pull the pin to disconnect the actuator, and see if the actuator runs full stroke by itself? If it does, the seat rails are blocking or the actuator bracket is mounted too far forward.
Clean the tracks and check if any bolts or blocks are stopping it. If you want, send pics of the actuator bracket and the rail ends and i will take another look.