The generated scaffold does not contain any logic to update collection properties of a JPA entity. This results in incorrect behavior when the collection is part of a bi-directional relationship in JPA.

This is because no logic exists to remove both sides of the relationship when an entity instance is removed from the collection. The result of this absence in logic is that removal of entities from collection properties do not succeed. Upon save, the collection returns to it's previous state.

Addition of members to the collection property are however performed correctly. Since the Faces scaffold does not allow updates to properties of the the individual members in the collection, no other issue is observed, except for the inability to update the collection state correctly.