Sounds like a stuck button. Had it happen on mine a few times. After pushing all the buttons a dozen times, whatever was sticking finally quit and all was good.
Capt. Craig Copeland
2013 Nautic Star 2110 Shallow Bay Boat
Humminbird HELIX 12 CHIRP MEGA SI GPS G2N
Nautic Star Boats Pro Staff (nauticstarboats.com)
Redneck Fish'n Jigs Pro Staff (redneckfishn.com)