If Pebble Flow's auto-dump keeps starting and stopping, add more water before retrying

We ran into a problem when the trailer was auto dumping. At first it was working great, then it got stuck with the pump coming off and on every few minutes. We aborted it by pressing the auto dump button again. There was not enough water in the tank towards the end. So maybe we needed to put more water in before filling it. After we added more water (by pumping water from the grey tank) (awesome option) it worked fine.