TypeOrm cannot create entity with lazy loading association

I'm using TypeOrm in my project and I'm facing the problem that I cannot create the entity with lazy load association within the .create() method, however, I can do it outside the .create() by assigning the property manually, am I doing something wrong?

@Entity()
export class TemplateEntity extends BaseEntity {
  @ManyToOne(
    () => CategoryEntity,
    (category) => category.templates,
  )
  category: Promise<CategoryEntity>;
}

@Entity()
export class CategoryEntity extends BaseEntity {
  @Column()
  name: string;

  @OneToMany(() => TemplateEntity, (template) => template.category)
  templates: Promise<TemplateEntity[]>;
}

const category1 = em.create(CategoryEntity, {
    name: 'cate_1',
});

const template1 = em.create(TemplateEntity, {
    name: 'temp_1',
    data: 'some json here',
    category: Promise.resolve(category1), //this is not working
});
console.log(await template1.category) //return a empty CategoryEntity{}

template1.category = Promise.resolve(category1);
console.log(await template1.category) //return category1