Grouping a pasted range

[KBSH]

Hello

I'm trying to copy and paste a certain range that needs to be pasted as a group. I've tried several things, but somehow it doesn't group the rows but the columns instead.
The code I'm using is:

 Public Sub NIEUWE_RUIMTE()
    Application.ScreenUpdating = False
    Dim Startrng     As Range
    Dim Endrng       As Range
        Rows.Hidden = False
        Rows("3:6").Copy
    ActiveSheet.Shapes(Application.Caller).TopLeftCell.Offset(0, -1).Select
        Do While ActiveCell.Value = "X"
             ActiveCell.Offset(1, 0).Select
        Loop
    Selection.Insert Shift:=xlDown, CopyOrigin:=xlFormatFromLeftOrAbove
    Set Startrng = ActiveCell.Offset(1, 0)
    Set Endrng = Startrng.Offset(2, 0)
    
    Range(Startrng, Endrng).Group
    
    Application.CutCopyMode = False
    ActiveSheet.Outline.ShowLevels RowLevels:=1
        Rows("2:7").EntireRow.Hidden = True
End Sub

It would be nice if someone could target my problem.