Не работает fetch Lazy для ManyToOne

Имеется такая структура БД

CREATE TABLE a (
    id            TEXT PRIMARY KEY,
    creation_date TIMESTAMP WITH TIME ZONE NOT NULL
);
CREATE TABLE b (
    id                TEXT,
    a_id              TEXT REFERENCES a,
    active            BOOLEAN                  NOT NULL,
    creation_date     TIMESTAMP WITH TIME ZONE NOT NULL,
    modification_date TIMESTAMP WITH TIME ZONE NOT NULL,
    version           INTEGER                  NOT NULL DEFAULT 0,
    PRIMARY KEY (id, a_id)
);
CREATE UNIQUE INDEX ON b (a_id) WHERE (active);
CREATE UNIQUE INDEX ON b (id) WHERE (active);
INSERT INTO a (id, creation_date) VALUES ('a_id', now());
INSERT INTO b (id, a_id, active, creation_date, modification_date) VALUES ('b_id', 'a_id', TRUE, now(), now());

JPA маппинг

@Entity
@Table(name = "a")
@EntityListeners(AuditingEntityListener::class)
class A(
    @Id
    var id: String
)  {
    @CreatedDate
    @Column(name = "creation_date", updatable = false)
    lateinit var creationDate: OffsetDateTime
}
@Entity
@Table(name = "b")
@EntityListeners(AuditingEntityListener::class)
class B(
    @EmbeddedId
    @AttributeOverride(name = "aId", column = Column(name = "a_id", updatable = false))
    var pk: Pk,
    var active: Boolean
) {
    @JoinColumn(name = "a_id")
    @MapsId("aId")
    @ManyToOne(cascade= [CascadeType.ALL], fetch = FetchType.LAZY)
    var a: A? = null
    @CreatedDate
    @Column(name = "creation_date", updatable = false)
    lateinit var creationDate: OffsetDateTime
    @LastModifiedDate
    @Column(name = "modification_date")
    lateinit var modificationDate: OffsetDateTime
    @Version
    var version: Int = 0
    @Embeddable
    class Pk(
        var id: String,
        var aId: String?
    ): Serializable {
        override fun equals(other: Any?): Boolean {
            if (this === other) return true
            if (javaClass != other?.javaClass) return false
            other as Pk
            if (id != other.id) return false
            if (aId != other.aId) return false
            return true
        }
        override fun hashCode(): Int {
            var result = id.hashCode()
            result = 31 * result + (aId?.hashCode() ?: 0)
            return result
        }
        companion object {
            private const val serialVersionUID: Long = 1L
        }
    }
}

Repository

interface BRepository : JpaRepository<B, B.Pk>

Когда я вызываю

bRepository.findById(B.Pk("b_id", "a_id"))

, то в логах hibernate появляется два запроса

Hibernate: select b0_.a_id as a_id1_1_0_, b0_.id as id2_1_0_, b0_.active as active3_1_0_, b0_.creation_date as creation4_1_0_, b0_.modification_date as modifica5_1_0_, b0_.version as version6_1_0_ from b b0_ where b0_.a_id=? and b0_.id=?
Hibernate: select a0_.id as id1_0_0_, a0_.creation_date as creation2_0_0_ from a a0_ where a0_.id=?

получается FetchType.LAZY в сущности B не отрабатывает, и A загружается.

Как исправить маппинг, чтобы A не загружался?