Incompatible sequence names between Liquibase and Hibernate JPA for PostgreSQL and H2
Use GenerationType.IDENTITY. This should work on most DBs.
Identity generation is one of the warts of JPA in my opinion; it's too hard to set global overrides for generation options based on the DB you're using, etc. Doing it in annotations makes it hard to adjust programmatically.
Hibernate's bizarre hibernate_sequence is particularly painful. It's beyond me why it doesn't use the PostgreSQL default sequences for generated columns.