Adjusting Major Units on Pivot Chart with Worksheet_PivotTableChangeSync

Hi All, I'm stuck on the correct way to call "Chart 1" (Pivot Chart) on my worksheet to allow a change of major axis value when filters are changed. I keep getting errors at the red highlighted code. I have this and have tried these and many other arrangements but am getting nowhere.

Could someone please set me straight?

Private Sub Worksheet_PivotTableChangeSync(ByVal Target As PivotTable)

    Dim mUnit As Long

    If Cells(LastRow, LastCol) / LastCol - 1 >= 30 Then
        mUnit = 10
    Else
        If Cells(LastRow, LastCol) / LastCol - 1 >= 200 Then
            mUnit = 50
        Else
            If Cells(LastRow, LastCol) / LastCol - 1 >= 500 Then
                mUnit = 100
            End If
        End If
    End If

    ActiveSheet.ChartObjects(1).Chart.Axes(xlValue).MajorUnit = mUnit

    'or

    ActiveSheet.Shapes("Chart 1").Axes(xlValue).MajorUnit = mUnit

End Sub

Many thanks,

I got around this by setting the MajorUnit to Auto and adjusting the MinorUnit to 1 when creating the Pivot Chart.

With ActiveChart
    .Axes().MajorUnitIsAuto = True
    .Axes(xlValue).MinorUnit = 1
End With

Many thanks!