Diagnosis
Moisture or grease has seeped under the membrane of the capacitive touch panel. This is common if you wipe the display with a wet cloth.
How to Fix It
Unplug the unit. Use a dry, lint-free microfiber cloth to thoroughly dry the entire control panel. Press firmly around the edges of the panel to seat it. Let it sit unplugged in a dry area for 24 hours to let internal moisture evaporate.
If That Didn't Work
The touch panel membrane is likely faulty. This requires a control board replacement. Cosori may cover this under warranty if the unit is relatively new.
Heads Up
Only clean the control panel when the unit is cool and unplugged. Use a barely-damp cloth, never a spray. Liquids dripping into the housing can cause permanent damage.