Microsoft 365 Grouper ou regrouper en VBA

Sub Construire()
Application.ScreenUpdating = False
Cells.EntireRow.Hidden = False
Cells.Clear
For L = 1 To 26
    Ligne = 21 * L - 20
    Lettre = Chr(64 + L)
    Rows(Ligne).Interior.Color = RGB(0, 0, 255)
    With Cells(Ligne, "A")
        .Font.Color = vbWhite
        .Font.Bold = True
        .Font.Size = 12
        .Value = Lettre
    End With
Next L
End Sub

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
On Error GoTo Fin
Ligne = Target.Row
If Cells(Ligne, "A").Interior.Color <> vbBlue Then Exit Sub
Application.ScreenUpdating = False
For L = 1 To 27
    Ldeb = 21 * L - 20 + 1
    Lfin = 21 * L - 20 + 1 + 20 - 1
    Rows(Ldeb & ":" & Lfin).EntireRow.Hidden = True
Next L
Ldeb = Ligne + 1
Lfin = Ligne + 21
Rows(Ldeb & ":" & Lfin).EntireRow.Hidden = False
Fin:
End Sub

Sub Grouper()
j = 1
For i = 1 To 546 Step 21
Cells(i, 1) = Chr(64 + j)
Cells(i, 1).Offset(1).Resize(20).EntireRow.Group
j = j + 1
Next
End Sub