fluxgate

I have a SPX30 autopilot interfaced to my C80. For the most part it works great. The only issue is the heading from the fluxgate gets messed up. I doesnt align with the COG or the fluid compass. I have to re-align it every time.

Could this be a sign that the fluxgate is going bad? 5 to 10 degrees off I can live with but sometimes its over 40. All are on magnetic north.

thanks
bill