DIAGNOSIS Spills are the usual culprit. Even a tiny splash of liquid (smoothie, water, cleaning spray) seeped under the silicone seal of the control panel can short out the capacitive touch sensors, making them act possessed.
FIX Unplug the blender immediately. 1) Wipe the entire control panel and base dry with a soft cloth. 2) Tilt the base on its side and let it air-dry in a warm, dry place for at least 24-48 hours. The goal is to let any internal moisture completely evaporate. 3) After it's fully dry, plug it back in and test it. Often, this reset is all it needs.
IF THAT DIDN'T WORK If the phantom presses continue or buttons are dead, the control panel circuit board is likely damaged by moisture or has failed. Unfortunately, this isn't a user-serviceable part. You'll need to reach out to Ninja support for a repair or to check if it's under warranty.
HEADS UP Be super careful when cleaning. Never submerge the base, and avoid spraying cleaner directly onto the control panel. Spray your cloth first, then wipe. Always make sure the pitcher isn't dripping when you take it off the base.