As I recall the Klik n Play example you got the graphics from used an actual user defined path to move around the track.
The pathfinding behavior in construct is probably not well suited for this. Typically you'd define waypoints you'd want to pass through before telling to to find the path. You'd only do this again when the end of the path was reached.
An example capx is always better than images, but it probably stops because the pathfinding behavior will slow to a stop when it hits the grid containing the destination location, so it may not collide with those sprites to pathfind again. Setting the cell size smaller could be an idea, but wouldn't be great for performance.