NEW GP1870F COURSE UP LINE WAIVERS

Hi, The display shows Course Up but the line rotates left and right as the boat turns. Shouldn't it stay straight up with the chart rotating as I turn? I go into the menu to re-select "course up" but doesn't seem to matter.
Thanks.

The course line is tied to your COG (course over ground) from your GPS. If your bow is bouncing, COG bouncing, so will your course line. You can adjust with your course smoothing.

thanks for the help.