To reproduce run following code and click button. Graphic disappear from button.


import javafx.application.Application;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.MenuItem;
import javafx.scene.control.SplitMenuButton;
import javafx.scene.layout.VBox;
import javafx.scene.paint.Color;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;

public class SplitMenuButtonText extends Application {

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

    private Parent getContent() {
        VBox list = new VBox(10);
        list.setTranslateX(20);
        list.setTranslateY(20);
        SplitMenuButton but = new SplitMenuButton(new MenuItem("menu item",new Rectangle(10,10,Color.RED)));
        list.getChildren().add(but);
        
        return list;
    }

    public void start(Stage stage) {
        stage.setX(100);
        stage.setY(100);
        stage.setWidth(200);
        stage.setHeight(200);
        Scene scene = new Scene(getContent());
        stage.setScene(scene);
        stage.setVisible(true);
    }
}