我的应用程序运行方式很奇怪。事实上，在调试时，我可以清楚地看到我的对象被持久化在db上，但在运行模式下，jpa似乎不会持久化它们。以下是源代码中的代码片段：

@Entity
@Table(name = "a", schema="myschema")
public class A implements Serializable{
    @Id
    @Column(name = "id", unique = true, nullable = false)
    @NotNull(message = "id can not be null")
    private UUID id = UUID.randomUUID();

    @JsonIgnore
    // @ManyToMany(fetch = FetchType.EAGER)
    @ManyToMany
    @JoinTable(name = "a_b", joinColumns = { @JoinColumn(name = "a_id") },
    inverseJoinColumns = { @JoinColumn(name = "b_id") }
  )
  private List<b> blist = new ArrayList<>();

  //omitted source code
}

@Entity
@Table(name = "b", schema="myschema")
public class B implements Serializable{
  @Id
  @Column(name = "id", unique = true, nullable = false)
  @NotNull(message = "id can not be null")
  private Integer id;

  @ManyToMany(mappedBy = "blist")
  @JsonIgnore
  private List<A> alist = new ArrayList<>();

  //omitted source code
}

 @Service
 public class MyService{
   //omitted source code
   public Optional<A> createCopy(A source, int bId) {
     B b = bRepository.findById(bId);
     A copy_ = this.copy(source);
     A target = aRepository.save(copy_);
     b.getAlist().add(target);
     bRepository.save(b);
     return Optional.of(target);
   }

   private A copy(A source){
     A target = new A();
     //copy one to one from source to target
     target.setB(source.getB());
     return target;
   }
 }

调试时我可以看到，打电话给 MyService#createCopy() 方法，新记录将持久化到表中的数据库中 a_b . 但是，当我运行服务器，然后继续调用 MyService#createCopy() ，中没有其他记录 a_b 得到持久化。
以前有人遇到过这种奇怪的行为吗？如果是的话，请怎么解决？