boat icon facing wrong way

[Lazybones]

I have an es127. Most of the time the boat icon is facing in the right direction on the chart (course up). When we get close to port, the icon faces perpdindcular to the the direction it should be showing. In fact it appears to show as if we are moving sideways. Inhave also tried changing charts, Navionics, c-map, etc. and it makes no difference.

This does not happen all the time. I have tried changing from heads up to course up to north up when this happens and the icon remains perpendicular. What can I do to have the icon point in the dierction we are moving?