When you create a course, Explore app seems to add an erroneous course point at the same location as the start of the course. See the following screenshot, it shows Point 2 which I did not add myself. I just created a course by clicking on the map, as evidenced by the shaping points.
This erroneous waypoints results in the default course point icon being shown on my GPSMAP H1 when I load the course.
This is with Explore app version 4.7.1 on iOS.