Tree harvester not refuelled by fuel station after recovery

Tree harvester accessed a part of the island that is originally inaccessible, using a ramp built dumping dirt. The dump trucks kept working on the ramp, making the area inaccessible again (which is a real problem, the trucks building the ramp also often get stuck in the ramp they themselves are building) so the harvester was stuck and I had to send it back to the depot. At the depot, the harvester finds itself unable to reach the fuel tanks. I know that a ramp would solve the problem, but there's a fuel station that should take care of refueling with trucks idling. Why does the tree harvester insist on going to get fuel instead of waiting to be refueled? Isn't avoiding that the purpose of the refueling station?