I've attached a movie. There are actually two issues, but I don't know, whether they are different.

One issue: at some moment I cannot move focus.
The second: at some moment focus is replaced by white text applying.

Code:

import javafx.application.Application;
import javafx.event.EventHandler;
import javafx.geometry.Side;
import javafx.scene.Scene;
import javafx.scene.control.ContextMenu;
import javafx.scene.control.Label;
import javafx.scene.control.MenuItem;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.Pane;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

public class JavaApplication41 extends Application {

    @Override
    public void start(Stage stage) {
        VBox root = new VBox();


        Pane test_pane = new Pane();
        test_pane.setPrefSize(600, 300);
        test_pane.setMaxSize(600, 300);
        root.getChildren().add(test_pane);

        final ContextMenu menu = new ContextMenu();
        final Label menu_label = new Label("Menu");
        menu_label.setOnMouseReleased(new EventHandler<MouseEvent>() {

            @Override
            public void handle(MouseEvent t) {
                if (menu.isShowing()) {
                    System.out.println("hide");
                    menu.hide();
                } else {
                    System.out.println("show");
                    menu.show(menu_label, Side.BOTTOM, 0, 0);
                }
            }
        });

        test_pane.getChildren().add(menu_label);

        reset(menu);

        Scene scene = new Scene(root, 300, 300);
        stage.setScene(scene);
        stage.show();
    }

    public static void main(String[] args) {
        launch(args);
    }

    protected void reset(ContextMenu menu) {
        menu.getItems().clear();
        for (int i = 0; i < 3; i++) {
            menu.getItems().add(new MenuItem("Menu item" + i));
        }
    }
}