Not validating belongs_to

[pardeyke]

I have a model like this:

class HumanResource < ApplicationRecord
  acts_as_tenant :tenant

  belongs_to :project, optional: true
  belongs_to :event, optional: true
  belongs_to :user, optional: true
  belongs_to :job, optional: true
end 

These are all optional but validated so that :project and :event can't be nil at the same time. Same goes for :user and :job.
When creating a new HumanResource and passing ids for Users or Jobs from another Tenant these are stored in the db and not validated. Am I doing something wrong here or what is it?