No Wonder!

    // v4.8.1.78 06-Oct-2018 -JpE-
    // Perfected v4.9.4.90 27-Nov-2018
    private void SortListByLastAccess()
    {
      PFS.Default.SortByAccess = false;
      var sortThese = listBox1.Items
        .Cast<string>().ToList();
      var info = sortThese.Select(
        str => new FileInfo(str)).ToList();
      var sorted = info.OrderBy(
        x => x.LastAccessTime).ToList();
      var list = sorted.Select(fileInfo =>
        fileInfo.FullName).ToList();
      var date = sorted.Select(fileInfo =>
        fileInfo.LastAccessTime).ToList();
      var c = list.Count;
      var list1 = new Collection<string>();
      var date1 = new Collection<string>();
      for (var i = c-1; i >= 0; --i)
      { list1.Add(list[i]);
        date1.Add(Convert.ToString(date[i])); }
      listBox1.Items.Clear();
      foreach (var file in list1)
        listBox1.Items.Add(file);
      GetSelected();
    }