enabled

Specifies whether the point mark hover effect is enabled when the mouse is over the point (defaults to true):

seriesSettings: {
    stepline: {
        pointMark:
            {
                activeSettings:
                    {
                        pointHoveredState:
                            {
                                enabled:false
                            }
                    }
            }
    }
}

This setting is demonstrated in the following example.