the boat heading on all the ones i have used ( Raymarine and Garmin) was linked to the heading sensor.
Does the course over ground heading roughly match the compass?
If not then the heading sensor is either miswired or faulty.
I don't think there is another setting as we had a faulty heading sensor and there was nothing i could to to stop the boat pointing in all sorts of random places on the plotter ( E120 wide Raymarine )
swimbo is my nav man and sometimes ours is facing the wrong way she says its something to do with orientation but cant remember how to change it while not by the screen