Strange closure of form.showmodal

[AntonioCuomo]

A unigui application consisting of FormLogin that launches a form with treemenu:

implementation

{$R *.dfm}

uses
  MainModule, uniGUIApplication, Bottiglie, Clienti, NuovoOrdine;

function UniForm_Menu: TUniForm_Menu;
begin
  Result := TUniForm_Menu(UniMainModule.GetFormInstance(TUniForm_Menu));
end;

procedure TUniForm_Menu.Clienti1Click(Sender: TObject);
begin
Form_Clienti.ShowModal();
end;

procedure TUniForm_Menu.NuovoOrdine1Click(Sender: TObject);
begin
Form_NuovoOrdine.ShowModal();
end;

procedure TUniForm_Menu.UniBitBtn1Click(Sender: TObject);
begin
 close;
end;

procedure TUniForm_Menu.Vini1Click(Sender: TObject);
begin
Form_Bottiglie.ShowModal();
end;

end.

 

All events that execute FormXXXX.showmodal when I close the form with CLOSE it returns to the FormMenu.
while with

procedure TUniForm_Menu.NuovoOrdine1Click(Sender: TObject);
begin
Form_NuovoOrdine.ShowModal();
end;

 

When the from is closed, it returns to the form_login and not to that of the Menu.

All forms are structured the same way.