I have a many to many relation between two entities users & organizations, as follows:

UserEntity

@ManyToMany(() => OrganizationEntity, organization => organization.users)
    @JoinTable({name: 'user_organizations'})
    public organizations: OrganizationEntity[];

OrganizationEntity

@ManyToMany(() => UserEntity, user => user.organizations)
    public users: UserEntity[];

now when I create it as follows, it works perfectly:

const user = new User({...params})
const organization1 = new Organization({...organizationParams1})
const organization2 = new Organization({...organizationParams2})
user.organizations = [organization1, organization2]
this.usersRepository.save(user)

but later when I need to add a new organization and save it, it gives unique constraint violation for (user_id, organization_id) as it tries to save the old user organizations again

const user = this.usersRepository.find(userId)
const newOrganization= new Organization({...organizationParams})
user.organizations.push(newOrganization)
this.usersRepository.save(user)

I expect it to only save the new organization being added to the user, not all of it related organizations

what can I do to fix this issue?