Pseudo code to reproduce the problem.
1. void OnFirstButtonClick(){ Chart.Series.Clear(); var series = new LineSeries() {RenderMode = SeriesRenderMode.Light}; Chart.Series.Add(series); } // I can see added series, it's OK2. void OnSecondButtonClick(){ Chart.Series.Clear(); var series = new LineSeries(); Chart.Series.Add(series); } // I see new series and series from the first step. Why?// If the first series are rendered with Full RenderMode, I see only the second.