Why are some homes in Indian Paintbrush not members of the HOA?

Some homes in Phase 4A and Phase 4B are not part of the HOA because the builder failed to file the proper paperwork when the homes were initially sold. As a result, those homes that did not join the HOA at time of the initial sale of the home or when asked afterwards, are not governed by the HOA and the HOA cannot ask these homeowners to comply with our convenants, policies and restrictions.