Just curious....did you have the "North lock" on?
If the chart plotter is set to course loc it will drive you nuts if your trying to squat over a point in the ocean. While I like the course loc for running in the fog I prefer to north lock it if I drifting a rip or wreck. I pretty sure if you north lock it and zoom in all the way you will eliminate the need for the chart to keep refreshing.
Is this making an sense
