relations > Display options: Auto-relate submission?

hi there,

[my problem]
my relation field does not show the button that offers to create new, auto-related content.
I am talking about BE > Create field > type = "relation" > FIELD TYPE specific configuration > Viewing - Submit related > Display options: -- Auto-relate submission > Show Button = "Yes".
This happens in FE and BE submit forms.

[what i want to achieve]
Say, i have actors and movies. I create a new actor. Actor is supposed to be related to several movies. Some movies do not yet exist. So I want to create those missing movies from within the create-actor-form.
(But maybe above mentioned button/feature is for something different?)

Something i missed to do?
thanks a lot!