Select all shapes with similar names: Runtime error 1004

[mrbarba]

I am having trouble selecting only the shapes that contain a specific string within the name. The red line in the code is my problem.
I am searching for all the shapes within the sheet, storing the names of the shapes I wan't in an array and placing the join output of the array into a string. I can't get past this point.

Sub autoAlignShapes2323()
    Dim shp As Shape
    Dim ws As Worksheet
    Dim iButtonNames As Variant
    Dim cnt As Byte
    Dim btnStr As String
    
    ReDim iButtonNames(1)
    Set ws = Sheet1
    cnt = 0
    
    For Each shp In ws.Shapes
        Debug.Print shp.Name
        If InStr(1, shp.Name, "_Sheet", vbTextCompare) > 1 Then
            ReDim Preserve iButtonNames(cnt)
            iButtonNames(cnt) = Chr(34) & shp.Name & Chr(34)
            cnt = cnt + 1
        End If
    Next

    btnStr = Join(iButtonNames, ", ")
    Debug.Print btnStr & vbNewLine & TypeName(btnStr)
    ws.Shapes.Range(Array(btnStr)).Select

End Sub