Brett Meyer commented on an issue
Hibernate ORM / Bug HHH-8544
HHH000386 Warning when saving entity with generated Id.
See https://forum.hibernate.org/viewtopic.php?f=1&t=1025359&start=0 for details.

The warning message "WARN o.h.e.j.internal.JdbcCoordinatorImpl - HHH000386: ResultSet had no statement associated with it, but was not yet registered" is logged when saving an entity with a generated Id.