ListBox not highlighting selection

[sparky2205]

Hi folks,
I have a ListBox on a spreadsheet that is populated via vba on Workbook Open.

Private Sub Workbook_Open()

Dim N As Long
    For N = 2 To ActiveWorkbook.Sheets.Count - 1
        Sheets("Setup").ListBox1.AddItem ActiveWorkbook.Sheets(N).Name
        If ActiveWorkbook.Sheets(N).Visible = False Then
            With Sheets("Setup").ListBox1
                .Selected(.ListCount - 1) = True
            End With
        End If
    Next N
    Sheets("Setup").ListBox1.Height = Sheets("Setup").ListBox1.ListCount * 15
    
End Sub

The purpose of the ListBox is to allow the user to click a ListBox Item, in this case a worksheet name, and have that worksheet hidden. Click again to unhide.

Private Sub ListBox1_Change()
Dim x As Long
Dim pw As String
pw = ""

On Error GoTo errhandler

ThisWorkbook.Unprotect pw
With ListBox1
    For x = 0 To ListBox1.ListCount - 1
    If ListBox1.Selected(x) = True Then
        Worksheets(ListBox1.List(x)).Visible = False
    Else
        Worksheets(ListBox1.List(x)).Visible = True
    End If
    Next x
End With
ThisWorkbook.Protect Password:=pw
Exit Sub

errhandler:
ThisWorkbook.Protect Password:=pw

End Sub

I opened the workbook on Friday (26 Apr) and while clicking a ListBox Item hid the associated worksheet, it did not highlight the ListBox Item.
I opened the workbook again on Monday (29 Apr) and everything worked fine. i.e. the ListBox populated correctly and when an item was clicked it hid/unhid the associated worksheet and highlighted/unhighlighted the ListBox Item.
I opened the workbook again today (Tuesday 30 Apr) and it behaves as it did last Friday i.e. clicking a ListBox Item hid the associated worksheet but did not highlight the ListBox Item.

Does anyone have an explanation/fix for this intermittent behaviour?