This is a more serious variation of https://hibernate.atlassian.net/browse/HSEARCH-4305 that only happens with Hibernate ORM 5.6.12+, 6.1.4+ and 6.2.0+.

Essentially, Hibernate Search is not getting a post-update event when a property annotated with @OneToOne(mappedBy = ...) is modified, so it does not trigger reindexing accordingly.