Robertson AP300 Autopilot

[mestrezat]

When I engage my Robertson AP300X, and turn on the Autopilot feature, I turn the knob to change the rudder direction. It's been fine before but now it only goes to 13 degrees to port or starboard before stopping. I'm doing this while tied up at a marina. While underway, it has turns the rudder far greater than that so is it only going to 13/14 degrees because I'm tied up and the autopilot won't let it go past that degree?