ais radar- pi and fluctuate compass?

[Rakoa]

As a computer incompetent apologies for asking what may already be answered.
Finally got radar overlay to work , even though the separate window did, by turning on the autopilot
..this obviously connected the heading compass..great, but is it possible to connect it directly so it works with auto pilot off?
Associated I think: the ais on chart works normally but the ais radar-pi plugin window shows the boats back to front...I have only a receiver I should say. So the boats around me all appear on top of each other in the middle of screen. I seem to appear as several locations, on the move. I can live happily as they are but anomallies like this usually lead to something fundamental. Using opencpn 5, radar-pi 1.1
Cheers, Jonathan