Non-constituent relationship records are not stand-alone records, and have to be linked to a full constituent.  In the case of non-constituent student records, these are relationship records that are created on the record of the parent.  There are two things that may prevent the parent record from being created or linked to the student:
  • If the parent relationship has not been added to the student's profile in Core
  • If the Parents checkbox is not marked in the Connect RE settings 
If either or both of these conditions exist, then there is no full constituent to create the relationship on, and so the Integration will default to creating a full constituent record for the student.