cant close windows()

Hi im trying to close a existing windows but i cant. the closeListener is active but the windows is still on screen
thanks you for help.

  Button btnNotification = new Button();
        btnNotification.setIcon(FontAwesome.BELL);
        btnNotification.setStyleName(ValoTheme.BUTTON_ICON_ONLY);
        btnNotification.addStyleName(ValoTheme.BUTTON_BORDERLESS);
        btnNotification.addClickListener(clickevent->{
        	
        	if (notificationsWindow == null) {
                notificationsWindow = new Window();
                notificationsWindow.setWidth(300.0f, Unit.PIXELS);
                notificationsWindow.addStyleName("notifications");
                notificationsWindow.setClosable(false);
                notificationsWindow.setResizable(false);
                notificationsWindow.setDraggable(false);
                notificationsWindow.addCloseListener(event->{System.out.println("Closed");});
               
                notificationsWindow.setContent(Notification());
            }
        	
        	if(!notificationsWindow.isAttached()) {
        	  notificationsWindow.setPositionY(clickevent.getClientY()
	                    - clickevent.getRelativeY() + 40);
	            notificationsWindow.setPositionX(100);
	                   
	            getUI().addWindow(notificationsWindow);
        	 notificationsWindow.focus();
        	}else {
        		
        		notificationsWindow.close();
        	}
	           
        });

Seems to work ok for me, once I fill in the missing parts:
https://www.youtube.com/watch?v=N516DVN64Lo&feature=youtu.be

Note that I made the test on 8.6.3. Maybe you have an earlier version?

the problem was my css style,it had some errors
thanks for you help