Rover boat RTH bench checks

*** Moved to boat section ****
I’m helping a friend to upgrade his boat, it has pixhawk mini as the AP with GPS and telemetry link to the transmitter.

I’m trying to check functionality of the system prior to entering the water.
Initiating RTH only starts the motor with no rudder movement at all, is it OK ?
should the boat move to initiate rudder movement ?
Also implemented waypoint acquisition with auto navigation mode … with the same result, no rudder movement.