Eager fetch nested (recursive) objects - Hibernate

I want to populate my object hierarchy eagerly. The problem is that at some point Hibernate stops from fetching; it leaves relation fields (lists) unpopulated.

The hierarchy is (some code is ommited like id's, getters, this part seems to be fine, hopefully):

public class User {
    private Container container;

    @OneToOne(fetch = FetchType.EAGER)
    public Container getContainer() {
        return container;
    }
}


public class Container {
    private List<Backpack> backpacks;
    private List<Item> items;

    @OneToMany(fetch = FetchType.EAGER, mappedBy="container")
    @Fetch(FetchMode.SELECT)
    private List<Item> getItems() {
        return items;
    }


    @OneToMany(fetch = FetchType.EAGER, mappedBy="container")
    @Fetch(FetchMode.SELECT)
    private List<Backpack> getBackpacks() {
        return backpacks;
    }
}


public class Backpack {
    ...
    private Container container;            /* Unidirectional relationship - ID of container which contains this backpack */
    private Container backpackContainer;    /* Unidirectional relationship - ID of container which represents backpack's storge */
    ...

    @NotNull
    @ManyToOne(fetch = FetchType.EAGER)
    @Fetch(FetchMode.SELECT)
    public Container getContainer() {
        return container;
    }


    @OneToOne(fetch = FetchType.EAGER)
    @Fetch(FetchMode.SELECT)
    public Container getBackpackContainer() {
        return backpackContainer;
    }
}

And the result:

User(
    uid=2,
    name=admin,
    ....,

    container=Container(
        id=1,

        items=[
            Item(...),
            Item(...),
            Item(...),
            Item(...)
        ],

        backpacks=[
            Backpack(
                container=1,

                backpackContainer=Container(
                    id=3,
                    items=null, /* Problem! Shouldn't be empty array [] at least or array with items? */
                    backpacks=null /* Problem! Shouldn't be empty array [] at least or array with backpacks? */
                )
            )
        ]
    )
)

As I annotated the result, nested fields items and backpacks are null, which suggests a huge problem. Hibernate tends to use empty sets instead of nulls, also I don't want to add null checkers everywhere.

What can cause this problem?

Also, this hierarchy is not infinite-deep, user's container may have as many backpacks as it wants, but those backpacks may not contain another backpacks.