Copy and Paste not working after running VBA code

[dandelion]

I have a pivot table in from D10 to L(lastrow) and a range (AA:AH) that will copy and paste a formula from Rows 9 to Rows 11 onward depending the number of last rows in pivot table.
However, There are 02 problem occuring when I run this code:
1. Copy and Paste stop working in any cells of the sheet
2. If I want to hide / group Rows 9 and 10, every rows from AH to AG are all deleted if not available value are selected from pivot (or lastrow of pivottable is smaller than last row of range AA:AH)

Please help. Thanks a lot

Private Sub Worksheet_SelectionChange(ByVal Target As Range)

Dim ws As Worksheet
Dim l_rPivot As Double
Dim l_rFormula As Double

Set ws = ActiveSheet

l_rPivot = ws.Cells(Rows.Count, "D").End(xlUp).Row
l_rFormula = ws.Cells(Rows.Count, "AD").End(xlUp).Row

If l_rPivot > l_rFormula Then
ws.Range("AA9:AH9").Copy
ws.Range(Cells(l_rFormula + 1, "AA"), Cells(l_rPivot, "AH")).PasteSpecial xlPasteAll

ElseIf l_rPivot < l_rFormula Then
ws.Range(Cells(l_rPivot + 1, "AA"), Cells(l_rFormula, "AH")).Delete Shift:=xlUp

End If

Application.CutCopyMode = False

End Sub