Dropdown list multiple select not working in protected sheet

Hey,

I have a sheet with several multiple select dropdown lists and need to have the worksheet protected. I've been using the below code in ThisWorkbook:

Private Sub Workbook_Open()
 
Dim ws As Worksheet
For Each ws In ThisWorkbook.Worksheets
ws.Protect Password:="xxxx", UserInterFaceOnly:=True
Next ws
 
End Sub

But when I protect the worksheet the below code stops working, but it was working before I locked it.

Private Sub Worksheet_Change(ByVal Target As Range)

Dim x As Range
Dim rngDV As Range
Dim oldVal As String
Dim newVal As String


If Not Intersect(Target, Columns(8)) Is Nothing Then
    If Target.Value Like "*Done*" Then
        Cells(Target.Row, 1).Copy Sheets("Post Campaign Tracker").Range("A" & Rows.Count).End(3)(2)
        Cells(Target.Row, 3).Copy Sheets("Post Campaign Tracker").Range("B" & Rows.Count).End(3)(2)
        Cells(Target.Row, 4).Copy Sheets("Post Campaign Tracker").Range("C" & Rows.Count).End(3)(2)
        Cells(Target.Row, 7).Copy Sheets("Post Campaign Tracker").Range("D" & Rows.Count).End(3)(2)
        Cells(Target.Row, 11).Copy Sheets("Post Campaign Tracker").Range("E" & Rows.Count).End(3)(2)
    Else
        Set x = Sheets("Post Campaign Tracker").Columns(1).Find(Cells(Target.Row, 1), LookIn:=xlValues, lookat:=xlWhole)
            If Not x Is Nothing Then
               Sheets("Post Campaign Tracker").Rows(x.Row).Delete
            End If
        Set x = Nothing
    End If
    Exit Sub
End If



If Target.Count > 1 Then GoTo exitHandler

On Error Resume Next
Set rngDV = Cells.SpecialCells(xlCellTypeAllValidation)
On Error GoTo exitHandler

If rngDV Is Nothing Then GoTo exitHandler

If Intersect(Target, rngDV) Is Nothing Then

Else
  Application.EnableEvents = False
  newVal = Target.Value
  Application.Undo
  oldVal = Target.Value
  Target.Value = newVal
 If Target.Column = 5 _
    Or Target.Column = 7 _
    Or Target.Column = 13 _
    Or Target.Column = 14 Then
    If oldVal = "" Then
      'do nothing
      Else
      If newVal = "" Then
      'do nothing
      Else
        lUsed = InStr(1, oldVal, newVal)
        If lUsed > 0 Then
            If Right(oldVal, Len(newVal)) = newVal Then
                Target.Value = Left(oldVal, Len(oldVal) - Len(newVal) - 2)
            Else
                Target.Value = Replace(oldVal, newVal & ", ", "")
            End If
        Else
            Target.Value = oldVal _
              & ", " & newVal
        End If
        
      End If
    End If
  End If
End If

exitHandler:
  Application.EnableEvents = True
  
End Sub

Any help would be much appreciated!

Thanks
Oscar