Your setup seems fine! It might help to drop everything and recreate the types and table from scratch just to be sure.

As for the previous response: there’s no need to define object_customers as t_business_person. Since t_persons is marked with NOT FINAL, it already supports inserting any sub-types, including t_business_person. If you defined the table as t_business_person, it would restrict the table to that specific sub-type, which limits flexibility.