Pivot Table VBA Slow

When I go to the actual pivot table it runs fast when I sort and pick manually, but for some reason this code runs very slow in this macro?

HTML Code: 

Application.ScreenUpdating = False
   Application.Calculation = xlCalculationAutomatic
   
Sheets("Pivot_Table (2)").Select
Range("B3").Select
    With ActiveSheet.PivotTables("PivotTable5").PivotFields("Group Name")
            If Range("N1") = 1 Then
        .PivotItems("Item1").Visible = True
        .PivotItems("Item2").Visible = True
        .PivotItems("Item3").Visible = True
        .PivotItems("Item4").Visible = True
        .PivotItems("Item5").Visible = True
        .PivotItems("Item6").Visible = True
        ............
        .PivotItems("Item32").Visible = True
        End If

I actually have this do this true or false if a certain pulldown is selected...so I have about 33 of these statements (depending upon which item is selected)

Like I said before, if I select all or refresh..the table updates very quickly.

There must be something different about how the 2 work????

has to be something in the code slowing it down????

That may be hard.

The data that feeds the table comes from different sheets and the whole book is now alittle over 20 meg.

I'd have to simulate the data in one sheet then redo the pivot table.
May take alittle bit to do, but I am willing if I can figure it out.

thanks for offering to help....let me see what i can do