Unable to change boundary of the marker in Excel line chart

Question

I have written the below code in VBA to make a line chart with dotted line style and also specific markers for only 1st and last data point. I do not want markers for all data points. In below code ch refers to the chart and variable i refers to series number

                With ch.SeriesCollection(i).Format.Line
                    .transparency = 0
                    .Style = msoLineSingle
                    .dashStyle = msoLineRoundDot
                    .ForeColor.RGB = RGB(0, 0, 0)
                End With
                
                ' Set markers for the first and last data points
                With sC.Points(1)
                    .MarkerStyle = xlMarkerStyleCircle
                    .MarkerSize = 5
                    .Format.Line.Visible = True
                    .Format.Line.weight = 1.25
                    If .MarkerStyle <> xlMarkerStyleNone Then
                        .MarkerBackgroundColor = RGB(255, 255, 255)
                    End If
                    .Format.Fill.Visible = False
                End With
                
                sC.Points(1).Select
                Selection.Format.Line.Visible = msoTrue
                Selection.Format.Line.dashStyle = msoLineSolid
                                
                With sC.Points(lastPoint)
                    .MarkerStyle = xlMarkerStyleCircle
                    .MarkerSize = 5
                    .Format.Line.Visible = True
                    .Format.Line.weight = 1.25
                    If .MarkerStyle <> xlMarkerStyleNone Then
                        .MarkerBackgroundColor = RGB(255, 255, 255)
                    End If
                    .Format.Fill.Visible = False
                End With

                sC.Points(lastPoint).Select
                Selection.Format.Line.Visible = msoTrue
                Selection.Format.Line.dashStyle = msoLineSolid

but the above code is making the last portion of the line also as continuous instead of just making the markers with solid line. I managed to get the first marker correct though.

Any pointers on this would be helpful

Shown below is the image