(a) If issues that may be resolved by agreement pursuant to Section 3178 are not resolved by an agreement of all the parties who participate in mediation, the mediator shall inform the court in writing and the court shall set the matter for hearing on the unresolved issues.
(b) Where a stepparent or grandparent requests visitation, each natural or adoptive parent and the stepparent or grandparent shall be given an opportunity to appear and be heard on the issue of visitation.