@OneToMany annotation property does not persist in a related entity

I have a scenario where I’m using the relationship @OneToMany bidirectional with hibernate, doing that I have the reference of the ID from my entity ServiceOrder in my entity ClinicalProcedure, the problem is when I try to persist the properties from my entity ServiceOrder the property that it’s annotated with @OneToMany it’s not persisting the id reference in my entity ClinicalProcedure, does anyone can help me with that? This is my project on GitHub

Changing a mappedBy association does not make an entity dirty, so if you want to assign a ClinicalProcedure to a ServiceOrder, you will have to persist a ClinicalProcedure that refers to an existing ServiceOrder.