Auto Mode Reverse Behavior

Hi all,
I’m trying to understand if or when arduboat will command reverse to a waypoint, and if so can I disable it. My boat runs fine 95% of the time but occasionally when I put it in auto, especially if close to the first waypoint it goes into reverse and oscillates wildly. Putting the vehicle into hold then back to auto usually solves the problem and the vehicle heads off forwards to the waypoint.