We have recently upgraded to Hibernate 6.2.5.Final. After updating, we noted an issue related to the max_fetch_depth parameter - depending on the value of max_fetch_depth, entity relationships defined on fetched entities as @ManyToOne and @OneToMany were being set to null rather than initialised with a proxy. This appears to be a bug to us because there is no way to now distinguish between absent data and data that should be lazily loaded.

A sample project together with failing tests has been created on GitHub: https://github.com/philiplowney/hibernate-max-fetch-depth-bug