Parent component simply not getting added

Entity Component System (ECS)
,
1

What am I doing wrong? I am trying to add a parent component to an entity but just does not work.
https://docs.unity3d.com/Packages/com.unity.entities@1.0/api/Unity.Transforms.Parent.html

        public void OnUpdate(ref SystemState state)
        {
            state.Enabled = false;
            EntityCommandBuffer ecb = new EntityCommandBuffer(Allocator.Temp);

            var theParent = ecb.CreateEntity();
            ecb.SetName(theParent, "The Parent");
            var theChild = ecb.CreateEntity();
            ecb.SetName(theChild, "The Child");
            ecb.AddComponent(theChild, new Parent { Value = theParent });   // Doesnt get added
            ecb.AddComponent(theParent, new SomeComponent { thingy = 4 });  // Added
            ecb.AddComponent(theChild, new SomeComponent { thingy = 2 });   // Added  

            ecb.Playback(state.EntityManager);
            ecb.Dispose();
        }
2

Okay it seems that parenting in runtime doesn’t work for entities created objects in a baked subscene. Instantiating a new entity from a prefab and adding the component works fine.

Would like to mark this solved but I don’t know how