To reproduce:
1. Select all and you will see the subject.

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.control.ListView;
import javafx.scene.control.SelectionMode;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;

public class JavaFXApplication16 extends Application {
    
    @Override
    public void start(Stage primaryStage) {
        ListView lv = new ListView();
        for (int i = 0; i < 10; i++) {
            lv.getItems().add(new Label("Label-" + i));
        }
        lv.getSelectionModel().setSelectionMode(SelectionMode.MULTIPLE);
        
        StackPane root = new StackPane();
        root.getChildren().add(lv);
        
        Scene scene = new Scene(root, 400, 300);
        
        primaryStage.setTitle("Hello World!");
        primaryStage.setScene(scene);
        primaryStage.show();
    }

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