Honestly I have no idea. I am not aware of this issue. The reason I asked about whether you are using a relay board is that using ‘active-low’ relays would be a obvious reason why the solenoids engage right in the beginning. Other than making sure the power adapter outputs AC (not DC) voltage, and making sure RPi is plugged in and aligned correctly with OSPi, I have no idea why it would engage the solenoids at power-on.