为什么b4和b5的fadein无效啊，求助

Cocos2d-x
#1 
auto b1 = Sprite::create("1.png");
auto b2 = Sprite::create("2.png");
auto b3 = Sprite::create("3.png");
auto b4 = Sprite::create("4.png");
auto b5 = Sprite::create("5.png");

b1->setAnchorPoint(Vec2(0, 0));
b2->setAnchorPoint(Vec2(0, 0));
b3->setAnchorPoint(Vec2(0, 0));
b4->setAnchorPoint(Vec2(0, 0));
b5->setAnchorPoint(Vec2(0, 0));

b1->setPosition(90, 170);
b2->setPosition(90, 170);
b3->setPosition(90, 170);
b4->setPosition(90, 170);
b5->setPosition(90, 170);

bg->addChild(b1, 1);
bg->addChild(b2, 1);
bg->addChild(b3, 1);
bg->addChild(b4, 1);
bg->addChild(b5, 1);

b1->setOpacity(255);
b2->setOpacity(0);
b3->setOpacity(0);
b4->setOpacity(0);
b5->setOpacity(0);

    auto fadein = FadeIn::create(0.01);
auto fadeout = FadeOut::create(0.01);
auto stay = DelayTime::create(3);
   
    b1->runAction(Sequence::create(stay, fadeout, NULL));
b2->runAction(Sequence::create(stay, fadein, stay, fadeout, NULL));
b3->runAction(Sequence::create(stay, stay, fadein,stay,fadeout, NULL));
b4->runAction(Sequence::create(stay,stay,stay,fadein,stay,stay,fadeout, NULL));
b5->runAction(Sequence::create(stay,stay,stay,stay,stay,fadein, NULL));