I have two tables that are related to each other in a bi-directional many to many relationship. There is a User and a Group table. If a group is created it should be saved to the join table, but that isn't happening. The Group is being created but the join table isn't being updated.

export class User {
  @PrimaryGeneratedColumn()
  id!: number;

  @ManyToMany(() => Group, (group) => group.users, {
    cascade: true,
  })
  @JoinTable()
  groups: Group[];
}

export class Group {
  @PrimaryGeneratedColumn()
  id!: number;

  @ManyToMany(() => User, (user) => user.groups)
  users: User[];
}

const u = await this.userRepository.findOne({
  where: {
    id: user.id,
  },
});

const newGroup = new Group();
newGroup.name = name;
await this.connection.manager.save(newGroup);

u.firstName = 'randy';
u.groups.push(newGroup);
await this.connection.manager.save(u);