Is this a 3D Camera bug?

I am using cocos2d-x 3.4final
I have a scene that have two models in it,one of the road and another is a car.
When i wrote code like this the car was covered by the road:

mCamera = Camera::createPerspective(60, vs.width/vs.height, 0.01, 2600);
mCamera->setCameraFlag(CameraFlag::USER1);
mCamera->setPosition3D(Vec3(vs.width/2, 0, 1100));
mCamera->lookAt(Vec3(vs.width/2,vs.height*3/5,0));
addChild(mCamera);

Sprite3D* test = Sprite3D::create("road.c3b");
test->setPosition3D(Vec3(vs.width/2, vs.height/2, 0));
test->setCameraMask((unsigned int)CameraFlag::USER1);
addChild(test);

Sprite3D* car1 = Sprite3D::create("car1.c3b");
car1->setPosition3D(Vec3(vs.width/2, vs.height/2,42.1));
car1->setCameraMask((unsigned int)CameraFlag::USER1);
addChild(car1);

This is the screen shot:

When i wrote code like this the car was displayed on the road :

mCamera = Camera::createPerspective(60, vs.width/vs.height, 0.01, 2600);
mCamera->setCameraFlag(CameraFlag::USER1);
mCamera->setPosition3D(Vec3(vs.width/2, vs.height/2, 1100));
mCamera->lookAt(Vec3(vs.width/2,vs.height/2,0));
addChild(mCamera);
//Other codes as same as the first codes

This is the screen shot:

All differences just two row.

the car was covered by the road:

mCamera->setPosition3D(Vec3(vs.width/2, 0, 1100));
mCamera->lookAt(Vec3(vs.width/2,vs.height*3/5,0));

The car was displayed on the road:

mCamera->setPosition3D(Vec3(vs.width/2, vs.height/2, 1100));
mCamera->lookAt(Vec3(vs.width/2,vs.height/2,0));

Is this a 3D Camera bug? or i worte the wrong code?

Yes,my question is why the car was dispeared or displayed?
You can see that the car’s position is always up to the road.

The draw order is determined by sorting the position at the center of the two sprites. Depending on the camera vector, they may sort differently.

The camera position and lookat position effects the results.

An example. You are using a camera to take picture.
There is a person in front, but you can not see the person in the camera if your camera does not target at him.