Has_many -- deletion from collection won't persist


Hallo – I have a class called LinkActorToActorGroupJoin (I know…)
as a has_many attribute in a class called ActorGroup.
My understanding is that deleting from
ActorGroup#link_actor_to_actor_group_joins should remove from this
collection & persist.
I’ve tried direct delete on objects in the collection, which remove
the object from the collection, but this is not persisted when I
reload the collection, as the object I previously deleted is back
Can anyone help?