We have an X5 on the old girl.
Polarity thing is a good possibility. If that does not work check the positioning of your fluxgate. I had the same problem with the whole learning thing and it turned out to be the fluxgate position.
"Said Hamlet to Ophelia, I'll draw a sketch of thee.
What kind of pencil shall I use? 2B or not 2B?” Spike Milligan