I'm on my second consecutive flight, with the same problem.I've loaded FSC and created and saved a flightplan. I have the GPS ticked, so it recognises where I am. The flightplan line is displayed. On the runway I set the rwy heading and click the A/P Heading button, etc, ready for takeoff. After takeoff I first engage A/P then click on the FSC's GPS window's Autoheading button. It goes green but doesn't follow the planned flight courses.
I've successfully done this often in the past. Have I forgotten summat? Gerry Winskill