AnchorPane keeps growing despite having maxWidth property set

I am building simple GUI where the root element StackPane is having two children: HBox and AnchorPane.

Having set maxWidth property for all children components to 600, AnchorPane still seems to grow horizontally when I only add any component to it and set this component's anchor to the value beyond 600.

As you can see in above screenshot - Label in a bottom-right corner has left anchor set to 700 which leads to increase in AnchorPane width.

I would rather have this Label cut or placed beyond visible space.

Why is that? Can I somehow force AnchorPane to keep its maximal bounds? Is there any workaround for this issue?

You can find related java(fx) code here.

I don't know why but, I tested it in SceneBuilder and changed some properties in fxml and it worked. I added minWidth to AnchorPane. This is my fork.