When given a water bucket, dispensers will always excrete the water upon being charged. Sometimes, it will be sucked back up again when it is decharged (as by a button). Other times, it will not. This happens at random. Recharging it and decharging will suck up all of the water buckets, even the ones that were glitched out the first time. Water should never be sucked up when decharged, only when charged a second time.