json-api-nestjs: 9.0.0

Hi! When I'm trying to save entity with null value, I get an error Validation error: Expected string, received null at \"data.attributes.code\""
But in schema this column is nullable

@Entity({ name: 'countries' })
export class Countries extends CommonColumns {
  @PrimaryGeneratedColumn()
  id: number;

  @Column({ name: 'title', length: 250 })
  name: string;

  @Column({ length: 3, nullable: true, default: 'NULL' })
  code: string;
}

patch body:

{"data":{"id":"1","attributes":{"name":"test","code":null},"type":"countries"}}

I don't use any controllers for this entity, it is just imported into entities array in app.module

I think that worked in 8.*.* version , but I'm not sure, because I'm migrating from old data base and before I could sent an empty string.

Maybe I need to add a validation rule now?