Hibernate does not save oneToMany

I have a relation 1 - > n between Connection and Reporting. The classes are as follows:

@Entity
@Table(name = "conexao")
public class Conexao {

 @Id
 @GeneratedValue(strategy = GenerationType.AUTO)
 @Column(name = "CONEXAO_ID", unique = true, nullable = false)
 private Long id;

@OneToMany(fetch = FetchType.LAZY, mappedBy="conexao")
private Set<Relatorio> relatorios;

  //getters and setters
}

The Report class:

@Entity
@Table(name = "relatorio")

public class Relatorio {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name = "RELATORIO_ID", unique = true, nullable = false)
private Long id;

@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "CONEXAO_ID")    
private Conexao conexao;

public Relatorio(Conexao conexao){
       this.coxexao = conexao;
}
   //getters and setters
}

I'm running like this:

   public Teste(){
   ConexaoDao  conDao = new ConexaoDao();
   Conexao con = conDao.buscar(new Long(6)); // aqui, tudo certo, ele tras a 
   conexao corretamente

  Relatorio relatorio = new Relatorio(con, "teste777", "teste555", "teste333");
  con.getRelatorios().add(relatorio);

  RelatorioDAO relDao = new RelatorioDAO();
  relDao.salvar(relatorio); // ele salva o relatorio, com a conexao preenchida corretamente

  }
}

The Daos:

public class ConexaoDAO {


public void salvar(Conexao conexao){
    Session sessao = HibernateUtil.getSessionFactory().openSession();
    Transaction transacao = sessao.beginTransaction();
    sessao.save(conexao);
    transacao.commit();
    sessao.close();
}

public void editar(List<Conexao> lista){
    Session sessao = HibernateUtil.getSessionFactory().openSession();
    Transaction transacao = sessao.beginTransaction();
    lista.forEach(conexao -> sessao.update(conexao));
    transacao.commit();
    sessao.close();
}

public void excluir(List<Conexao> lista){
    excluirRelatorio(lista);

    Session sessao = HibernateUtil.getSessionFactory().openSession();
    Transaction transacao = sessao.beginTransaction();
    Query query;
    for(Conexao conexao: lista){
        query = sessao.createQuery("delete Conexao where id = :id");
        query.setParameter("id", conexao.getId());
        query.executeUpdate();
    }
    transacao.commit();
    sessao.close();

}

private void excluirRelatorio(List<Conexao> lista){
    List<Relatorio> listaRelatorioExclusaoDummy = new ArrayList<Relatorio>();
    Set<Relatorio> setDummy;

    for(Conexao conexao: lista){
        setDummy = conexao.getRelatorios();
        listaRelatorioExclusaoDummy.addAll(setDummy);
    }
    RelatorioDAO relatorioDao = new RelatorioDAO();
    relatorioDao.excluir(listaRelatorioExclusaoDummy);
}



public List<Conexao> listar(){
    Session sessao = HibernateUtil.getSessionFactory().openSession();
    Query query = sessao.createQuery("from Conexao"); 
    List<Conexao> conexoes = query.list();
    sessao.close();
    return conexoes;
}


public Conexao buscar(Long id){
    Session sessao = HibernateUtil.getSessionFactory().openSession();
    Conexao conexao = (Conexao) sessao.get(Conexao.class, id);
    sessao.close();
    return conexao;
}

public void excluir(Conexao conexao){
    Session sessao = HibernateUtil.getSessionFactory().openSession();
    Transaction transacao = sessao.beginTransaction();
    sessao.delete(conexao);
    transacao.commit();
    sessao.close();
}

public void editar(Conexao conexao){
    Session sessao = HibernateUtil.getSessionFactory().openSession();
    Transaction transacao = sessao.beginTransaction();
    sessao.update(conexao);
    transacao.commit();
    sessao.close();
}


}

E Reporting:

public class RelatorioDAO{

public void excluir(List<Relatorio> lista) {
    excluirColuna(lista);

    Session sessao = HibernateUtil.getSessionFactory().openSession();
    Transaction transacao = sessao.beginTransaction();
    Query query;
    for(Relatorio relatorio: lista){
        query = sessao.createQuery("delete Relatorio where id = :id");
        query.setParameter("id", relatorio.getId());
        query.executeUpdate();
    }
    transacao.commit();
    sessao.close();
}

private void excluirColuna(List<Relatorio> lista){
    List<Coluna> listaColunaExclusaoDummy = new ArrayList<Coluna>();
    Set<Coluna> setDummy;

    for(Relatorio relatorio: lista){
        setDummy = relatorio.getColunas();
        listaColunaExclusaoDummy.addAll(setDummy);
    }
    ColunaDAO colunaDao = new ColunaDAO();
    colunaDao.excluir(listaColunaExclusaoDummy);
}

public void editar(List<Relatorio> listaRelatorioDummy) {
    Session sessao = HibernateUtil.getSessionFactory().openSession();
    Transaction transacao = sessao.beginTransaction();

    listaRelatorioDummy.forEach(relatorio -> sessao.update(relatorio));

    transacao.commit();
    sessao.close();
}

public void salvar(Relatorio relatorio) {
    Session sessao= null;
    try{
        sessao = HibernateUtil.getSessionFactory().openSession();
        Transaction transacao = sessao.beginTransaction();
        sessao.save(relatorio);
        transacao.commit();
    }finally{
        sessao.close();
    }
}

public List<Relatorio> listar() {
    Session sessao = HibernateUtil.getSessionFactory().openSession();
    Query query = sessao.createQuery("from Relatorio"); 
    List<Relatorio> relatorios = query.list();
    sessao.close();
    return relatorios;
}


}

and my HibernateUtil class:

public class HibernateUtil {

private static final SessionFactory sessionFactory = buildSessionFactory();

private static SessionFactory buildSessionFactory() {
    try {
        // Create the SessionFactory from hibernate.cfg.xml
        return new Configuration().configure().buildSessionFactory();
    } catch (Throwable ex) {
        // Make sure you log the exception, as it might be swallowed
        System.err.println("Initial SessionFactory creation failed." + ex);
        throw new ExceptionInInitializerError(ex);
    }
}

public static SessionFactory getSessionFactory() {
    return sessionFactory;
}

public static void shutdown() {
    // Close caches and connection pools
    getSessionFactory().close();
}
}

However, when I load the report, it after connecting to the null fields. So when I debugged the code, I checked that the connection passed as a parameter to the Report builder, is filled with all the fields.

The strangest thing is that when I look at Postgres, the reporting table has the column CONEXAO_ID filled in correctly. I do not understand why Java is not bringing the connection to all nulls. The connection brought in is not null, but its fields are. Could someone help me ???

I'll put the images to be more explicit:

This image shows the connection set in report. As you can see, the connection fields are all filled in.