Sorting TObjectList<T> swaps equal values

I have the following (simplified) class definition:

  TMyObject = class
  private
    FDoubleValue: Double;
    FText: string;
  protected
  public
    constructor Create(ADoubleValue: Double; AText: string);
    property DoubleValue: Double read FDoubleValue write FDoubleValue;
    property Text: string read FText write FText;
  end;

The following sample code, shows how I am sorting the TObjectList<TMyObject> (FMyObjects) and displaying them in a TListBox.

constructor TfrmMain.Create(AOwner: TComponent);
begin
  inherited;
  FMyObjects := TObjectList<TMyObject>.Create;
  FMyObjects.OwnsObjects := true; // Default but for clarity
end;

destructor TfrmMain.Destroy;
begin
  FMyObjects.Free;
  inherited;
end;

procedure TfrmMain.FormCreate(Sender: TObject);
var
  ii: Integer;
begin
  FMyObjects.Add(TMyObject.Create(100.00, 'Item 1'));
  FMyObjects.Add(TMyObject.Create(200.00, 'Item 2'));
  FMyObjects.Add(TMyObject.Create(300.00, 'Item 3')); // Duplicate sort value
  FMyObjects.Add(TMyObject.Create(300.00, 'Item 4')); // Duplicate sort value
  FMyObjects.Add(TMyObject.Create(400.00, 'Item 5'));
  ObjectsToListBox;
end;

procedure TfrmMain.SortList;
var
  Comparer: IComparer<TMyObject>;
begin
  Comparer := TDelegatedComparer<TMyObject>.Create(
    function(const MyObject1, MyObject2: TMyObject): Integer
    begin
      result := CompareValue(MyObject1.DoubleValue, MyObject2.DoubleValue, 0);
    end);
  FMyObjects.Sort(Comparer);
end;

procedure TfrmMain.ObjectsToListBox;
var
  ii: Integer;
begin
  ListBox1.Items.Clear;
  for ii := 0 to FMyObjects.Count - 1 do
    ListBox1.Items.Add(Format('%d - %.1f - %s', [ii, FMyObjects[ii].DoubleValue, 
       FMyObjects[ii].Text]));
end;

procedure TfrmMain.Button1Click(Sender: TObject);
begin
  SortList;
  ObjectsToListBox;
end;

Every time Button1 is clicked (and the list sorted), FMyObjects[2] (Item3) and FMyObjects[3] ('Item4') swap position in the list. In my "real world" (drawing) application this is undesirable.

I also experimented with different values for Epsilon in the CompareValue function call and also a different implementation of the anonymous function (comparing values and returning 1, -1 or 0), but neither seems to make a difference.

Am I missing something (e.g. a property that controls this behavior) or is this "by design" and it cannot be prevented?