Philip Lowney ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=5c18c2f... ) *created* an issue Hibernate ORM ( https://hibernate.atlassian.net/browse/HHH?atlOrigin=eyJpIjoiZjhkYTVhZTZm... ) / Bug ( https://hibernate.atlassian.net/browse/HHH-16871?atlOrigin=eyJpIjoiZjhkYT... ) HHH-16871 ( https://hibernate.atlassian.net/browse/HHH-16871?atlOrigin=eyJpIjoiZjhkYT... ) Queries returning null values for related entities depending on 'max_fetch_depth' ( https://hibernate.atlassian.net/browse/HHH-16871?atlOrigin=eyJpIjoiZjhkYT... ) Issue Type: Bug Affects Versions: 6.2.5 Assignee: Unassigned Components: hibernate-core Created: 29/Jun/2023 08:12 AM Priority: Major Reporter: Philip Lowney ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=5c18c2f... ) 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 ( https://hibernate.atlassian.net/browse/HHH-16871#add-comment?atlOrigin=ey... ) Add Comment ( https://hibernate.atlassian.net/browse/HHH-16871#add-comment?atlOrigin=ey... ) Get Jira notifications on your phone! Download the Jira Cloud app for Android ( https://play.google.com/store/apps/details?id=com.atlassian.android.jira.... ) or iOS ( https://itunes.apple.com/app/apple-store/id1006972087?pt=696495&ct=Em... ) This message was sent by Atlassian Jira (v1001.0.0-SNAPSHOT#100227- sha1:d7f1864 )