Unless these seats are different than most other power sets, there will be a screw drive arrangement (lead screw) that's powered by the motor, so it would take a really solid obstruction at the end of the rails to stop it. Similarly, screw drives of this nature cannot be back-driven. Given that, you can help narrow down a bit by attempting to operate the power seat while also pushing on the seat yourself. If that gets it to move, I believe that narrows it down to excessively gunked or obstructed seat rails, the seat rails getting cocked and bound up by hitting the limit of travel (only true if there is a single lead screw on one seat rail but not the other)... or the possibility that the mechanism is simply allowed to run completely off from the lead screws in that direction of travel (so if you run the seat "too far", the screw and nut disengage from one another). If that doesn't get it to move, then the sound could help narrow it down further. If the motor sounds like it's not under any load, or if there is clicking or crunching, then that points to something broken or the mechanism - with the arrangements I've seen, that would mean the mating nut for the lead screw stripping out. If you don't hear the motor working, then there's possibility it could be the motor but since this problem coincided with you moving the seat to the end of its travel, I would lean toward the lead screw being jammed. If there is something for a hard stop limiting its movement in that direction, then the lead screw would bind up in its mating nut if run too hard against it. If there is nothing for a hard stop, but the screw hasn't turned all the way out from the nut yet, that could indicate an obstruction in the threads of the leadscrew at the far end. Verifying, and fixing, most of those scenarios involves getting access to the lead screw(s) (presumably within the seat rails).

I wish I was more familiar with these particular seats, but I haven't had mine out yet.