Minn Kota GPS problems

I have a new MK terrova with bluetooth and the heading compass. When I use advanced tracking the motor swings side to side at 45 degree angles left to right constantly. Spot lock is also wonky occasionally getting into a mode where is go rabbit full speed side to side. Almost through me out of boat once. I have replaced the head of the unit but that did not fix anything. MK tech says to install the heading compass as other people have had that fix similar issues. Manuel says heading compass is only for using the jog feature. Has anyone had any issues like that where installing the heading compass helped? Right now I wish I had gone with the XI5.