When I switch in simulator resolutions to:
10.6" 1920 X 1080
10.6" 2560 X 1440
then when I navigate to page with chart control I get an excaption:
System.NotSupportedException
at System.IO.UnmanagedMemoryStream.Write(Byte[] buffer, Int32 offset, Int32 count)
at Syncfusion.UI.Xaml.Charts.WriteableBitmapExtensions.Clear(WriteableBitmap bmp, Stream stream, Byte[] pixels)
at Syncfusion.UI.Xaml.Charts.Chart.ClearBuffer()
at Syncfusion.UI.Xaml.Charts.Chart.ArrangeOverride(Size finalSize)
It also happens in you sample browser. It happens only on 10.6" screens, on 23" and 27" with the same resolution it is ok.