Weed Does Not Move When Changing Warehouse Z Level

Description: Weed plants do not move when changing the z level of your house/warehouse.

Reproduction Steps:

1: Plant weed. Grow weed.

2. View them in their glory, you grew those majestic plants.
3. Change the z level of your property.
4. Cry because they are no longer there.
5. Accidentally move the camera outside the shell while decorating and find them at the z level your warehouse was previously at.

Expected Behaviour:
The plants should move with the shell of the house/warehouse.

Actual Behaviour: They don't.

Screenshots: None unfortunately. Pretty easy to duplicate though.