JavaFX 场景的显示随机延迟

我创建了一个 JavaFX 应用程序（在 Ubuntu、Java™ SE 运行时环境（版本 1.8.0_131-b11）上运行）并制作了一个简单的测试应用程序：

  public class DelayedSceneApplication extends Application {
    @Override
    public void start(Stage primaryStage) throws Exception {
        primaryStage.setTitle("Test");
        primaryStage.setResizable(false);

        // Root.
        BorderPane root = new BorderPane();
        Scene scene = new Scene(root);
        primaryStage.setScene(scene);

        // Buttons box.
        HBox buttonBox = new HBox();
        buttonBox.setPadding(new Insets(10));
        buttonBox.getChildren().addAll(new Button("Test"));

        root.setBottom(buttonBox);
        primaryStage.show();
    }
  }

问题是，有时在舞台显示后，场景未加载。有时需要一秒钟才能显示按钮，有时会超过 20 秒。当场景尚未显示时，点击场景，该按钮立即显示。同样，有时该按钮在启动时会正确显示。正如随机提到的，这种情况会发生。要重现此行为，必须多次重新启动应用程序。我哪里做错了？这是错误吗？它是否可能无法在其他环境（Windows、其他 JAVA 版本...）中重现？

非常感谢！

Update:输出与-Dprism.verbose=true option:

Prism pipeline init order: es2 sw 
Using java-based Pisces rasterizer
Using dirty region optimizations
Not using texture mask for primitives
Not forcing power of 2 sizes for textures
Using hardware CLAMP_TO_ZERO mode
Opting in for HiDPI pixel scaling
Prism pipeline name = com.sun.prism.es2.ES2Pipeline
Loading ES2 native library ... prism_es2
    succeeded.
GLFactory using com.sun.prism.es2.X11GLFactory
(X) Got class = class com.sun.prism.es2.ES2Pipeline
Initialized prism pipeline: com.sun.prism.es2.ES2Pipeline
Maximum supported texture size: 16384
Maximum texture size clamped to 4096
Non power of two texture support = true
Maximum number of vertex attributes = 16
Maximum number of uniform vertex components = 16384
Maximum number of uniform fragment components = 16384
Maximum number of varying components = 128
Maximum number of texture units usable in a vertex shader = 32
Maximum number of texture units usable in a fragment shader = 32
Graphics Vendor: Intel Open Source Technology Center
       Renderer: Mesa DRI Intel(R) Kabylake GT2 
        Version: 3.0 Mesa 17.0.3
 vsync: true vpipe: true
ES2ResourceFactory: Prism - createStockShader: FillPgram_Color.frag
new alphas
ES2ResourceFactory: Prism - createStockShader: Texture_Color.frag
ES2ResourceFactory: Prism - createStockShader: Texture_LinearGradient_PAD.frag
ES2ResourceFactory: Prism - createStockShader: Solid_TextureRGB.frag
ES2ResourceFactory: Prism - createStockShader: Solid_TextureFirstPassLCD.frag
ES2ResourceFactory: Prism - createStockShader: Solid_TextureSecondPassLCD.frag