Continuous Power to Solenoid on Tablet Dispenser

The power stays on continuously to the Tablet Dispenser Solenoid, there is a slight hum / vibration and the tablet hatch stays open and won't close (because the Solenoid is activated). Borh the Dispenser and Button panel have been replaced but the problem remains. Why might voltage be continuously be fed to the solenoid ? WHIRLPOOL Model WIC 3C33 PFE UK, bought Feb'22, (2.5yrs) Ireland, light usage, 3times a week ... Your help appreciated, Thx