DIAGNOSIS: Moisture or condensation has gotten behind the capacitive touch panel, causing phantom inputs. Yeah, it's ironic for a water appliance.
FIX: Unplug the unit. Dry the entire exterior, especially the screen area, with a soft, dry cloth. Then, leave it unplugged in a warm, dry spot for at least 24 hours. This lets any internal condensation evaporate. When you plug it back in, it should behave normally.
IF THAT DIDN'T WORK: A hard reset can clear a software glitch. Unplug the machine. Press and hold the physical power button (if it has one) for 30 seconds while it's unplugged. Then plug it back in and power on.
HEADS UP: Avoid wiping the screen with a wet cloth or spray cleaner directly on it. Always wring out your cleaning cloth completely. The seal around the screen isn't perfect.