SpringBatch and Hibernate : Illegal attempt to associate a collection with two open sessions

Question

Trying to write a simple SpringBatch job with a chunk based on Hibernate reading HibernateCursorItemReader and writing HibernateItemWriter and I get the following error : org.hibernate.HibernateException: Illegal attempt to associate a collection with two open sessions. Collection : [Author.bookList#50]

    <job xmlns="http://www.springframework.org/schema/batch"
        id="rien" incrementer="simpleIncrementer">
        <step id="chunk">
            <tasklet>
                <chunk reader="reader" processor="processor" writer="writer" commit-interval="10"/>
            </tasklet>
        </step>
    </job>

    <bean id="reader" class="org.springframework.batch.item.database.HibernateCursorItemReader">
        <property name="useStatelessSession" value="false" />
        <property name="sessionFactory" ref ="sessionFactory" />
        <property name="queryString" value="from Author" />
    </bean>
    
    <bean id="processor" class="Processeur" />

    <bean id="writer" class="org.springframework.batch.item.database.HibernateItemWriter">
        <property name="sessionFactory" ref="sessionFactory" />
    </bean>
    
    <bean id="sessionFactory" class="org.springframework.orm.hibernate5.LocalSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="packagesToScan">
            <array>
                <value>[OBJECT_PATH]</value>
            </array>
        </property>
        <property name="hibernateProperties">
            <props>
                <prop key="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</prop>
                <prop key="hibernate.temp.use_jdbc_metadata_defaults">false</prop>
                <prop key="hibernate.connection.autocommit">false</prop>
                <prop key="hibernate.jdbc.batch_size">50</prop>
                <prop key="hibernate.order_inserts">true</prop>
                <prop key="hibernate.order_updates">true</prop>
                <prop key="hibernate.batch_versioned_data">true</prop>
                <prop key="hibernate.show_sql">true</prop>
            </props>
        </property>
    </bean>

@Entity
@Table(name = "book", schema = "mde")
public class Book implements Serializable
{
    private static final long serialVersionUID = 6466106157952706315L;

    @Id
    @Column(name = "ID")
    private Long id;

    @Column(name = "VALUE")
    private String value;

    @ManyToOne(cascade = CascadeType.ALL)
    @JoinColumn(name = "author_id")
    private Author author;

@Entity
@Table(name = "author", schema = "mde")
public class Author implements Serializable
{
    private static final long serialVersionUID = -6248898317777915222L;

    @Id
    @Column(name = "ID")
    private Long id;

    ...

    @OneToMany(mappedBy = "author", cascade = CascadeType.ALL, fetch = FetchType.EAGER, orphanRemoval = true)
    private List<Book> bookList;

public class Processeur implements ItemProcessor<Author, Author>
{
    @Override
    public Author process(Author author) throws Exception
    {
        for (Book item : author.getBookList())
        {
            item.setValue("99");
        }
        return author;
    }
}

Removing cascade = CascadeType.ALL does not help at all