hibernate auto generated sequence on non primary key field

Question

I was using hibernate 5.5 + postgresql 13

I want to have auto generated sequence field (auto gen on database side instead of java side), which is equivalent to this DDL in postgres:

CREATE TABLE map_objects (
        oid BIGSERIAL NOT NULL, 
        vid BIGSERIAL NOT NULL, 
        msg VARCHAR, 
        PRIMARY KEY (vid)
);

as you can see in the DDL, both vid and oid is auto gen in db side, however vid is pk but oid is not

after I run this plain DDL sql in psql, I got 1 table and 2 sequences, the 2 sequences are used to generate default values for vid and oid

                                  Table "public.map_objects"
 Column |       Type        | Collation | Nullable |                 Default                  
--------+-------------------+-----------+----------+------------------------------------------
 oid    | bigint            |           | not null | nextval('map_objects_oid_seq'::regclass)
 vid    | bigint            |           | not null | nextval('map_objects_vid_seq'::regclass)
 msg    | character varying |           |          | 

I want to have a equivalent definition in hibernate entity declaration, here is what I've tried:

@Entity
public class MapObject {
    @Id
    @Generated(GenerationTime.INSERT)
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long vid;

    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Generated(GenerationTime.INSERT)
    private Long oid;

    private String msg;

}

the vid is good, but the oid is not working in the way I expected, it was inserting null value for oid, not even having an auto-gen value in java side.

try2: GenerateType.SEQUENCE, but no luck.

try3:

    @Column(name = "oid", columnDefinition = "BIGSERIAL", nullable = true)
    private Long oid;

this approach basically manually define the column and the ORM know nothing about the entity, so after I insert the object, hibernate won't populate the generated oid from db, it's still null in Java side, therefore this is still not my expected behavior....