If I place a horizontal container and give it a height of 40, then nest other horizontal containers in it with Height = Parent.Height it seems that they do not accept the height.
In this example, the container that I just added keeps a Height of 200 even though the Parent.Height is displaying as 40.

If I change the child Height to Height = ContainerName.Height, it works.
Shouldn't a nested container be able to accept the height?