Wake Plate Motor Running Continuously

We dropped in last weekend and after cruising a bit and then killing the engine, I heard what I thought was the bilge pump running. Turned out to be the smart plate. I'm not sure if it was in the up or down position but it kept running continuously till I killed the battery switch. We surfed for a few hours after that with no issues at all. Then, after trailering the boat and pulling out of the water, the plate motor again starts running continuously. Would only stop after the turning the battery off. A storm was closing fast so I didn't have time to troubleshoot at the ramp.

Yesterday, with the boat on the trailer I turned the key to the on position and was able to lower/raise the plate with no issues. Has anyone ever had an issue like that before? Any ideas of a possible cause or things I can check if it happens again? Thanks!

- Jared