Task succeeds but the service onSucceed method is not triggered

When the Task includes 2 lines opening a stream and closing it, the Task returns correctly. Its succeed method runs. But the Service' setOnSucceeded method does not run. Why?

When the 2 lines about the streaming opening and closing are commented out in the Task, we do get the expected behavior: System.out.println("in the succeed method of the Service") does print.

The Main method:

package Test;

import javafx.application.Application;
import javafx.concurrent.Worker;
import javafx.stage.Stage;

public class Main extends Application {

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

    @Override
    public void start(Stage primaryStage) {

        MyService pluginUpdateService = new MyService();
        pluginUpdateService.setOnFailed(e -> {
            System.out.println("task failed");
        });
        pluginUpdateService.setOnSucceeded(e -> {
            System.out.println("in the succeed method of the Service"); // this does not print, when MyTask opens the stream (see code of MyTask)
        });
        // launching the service
        if (pluginUpdateService.getState() == Worker.State.READY) {
            pluginUpdateService.start();
        }
    }
}

The service MyService

package Test;

import javafx.concurrent.Service;
import javafx.concurrent.Task;

public class MyService extends Service {

    public MyService() {
    }

    @Override
    protected Task createTask() {
        Task updater = new MyTask();
        return updater;
    }
}

The task MyTask:

package Test;

import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import javafx.concurrent.Task;


public class MyTask extends Task {


    public MyTask() {

    }

    @Override
    protected Void call() throws MalformedURLException, IOException {
        InputStream in;
            URL url = new URL("https://clementlevallois.net");
            in = url.openStream(); // when this line is commented out, the Service does trigger its setOnSucceeded method as expected
            in.close(); // when this line is commented out, the Service does trigger its setOnSucceeded method as expected
        System.out.println("about to return from the call method of the Task");
        return null;
    }

    @Override
    protected void succeeded() {
        super.succeeded();
        System.out.println("succeeded - sent from the succeeded method of the Task");
    }

    @Override
    protected void cancelled() {
        super.cancelled();
        System.out.println("cancelled");
        updateMessage("Cancelled!");
    }

    @Override
    protected void failed() {
        super.failed();
        System.out.println("failed");
        updateMessage("Failed!");
    }

}