Eclipselink Shared Cache - Lazy associations - eclipselink

Question

I'm devoloping an application using JPA eclipselink 2.6.4.
I'm enabling the shared cache for serveral JPA entities.
#Entity
#Cache(
type=CacheType.SOFT,
size=500
)
public class Tutor
{
#Id
#Column(name = "id")
private String id;
#Column(name = "name")
private String name;
... getters and setters
}
#Entity
#Cache(
type=CacheType.SOFT,
size=500
)
public class Student
{
#Id
#Column(name = "id")
private String id;
#Column(name = "name")
private String name;
#ManyToOne(fetch=FetchType.LAZY)
#JoinColumn(name="TUTOR_ID")
private Tutor tutor;
... getters and setters
}
I got a typical entity association of tutor and students. It is defined as LAZY because we want to avoid the "N + 1 problem" when a students query is done.
When we execute a students query and we want the association to be resolved, we use JOIN FETCH technique:
SELECT s FROM Student s JOIN FETCH s.tutor t WHERE s.id = :id
Up here all right.
The first time we execute the JPA query, because shared cache has no students yet, a database query is executed. We get the student entity populated with the tutor entity.
Nevertheless, the second time we execute the same query, there is a hit in the shared cache, so a database query is NOT executed. But then the student entity IS NOT populated with the tutor entity.
We would like to get the student entity populated with the tutor entity.
We have seen that this is possible changing the association to EAGER, but we don't want to change to EAGER to avoid "N + 1 problem".
Any idea?
Thanks