Moritz Becker ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=557058%... ) *created* an issue Hibernate ORM ( https://hibernate.atlassian.net/browse/HHH?atlOrigin=eyJpIjoiZWRmNmE3NjYz... ) / Bug ( https://hibernate.atlassian.net/browse/HHH-16960?atlOrigin=eyJpIjoiZWRmNm... ) HHH-16960 ( https://hibernate.atlassian.net/browse/HHH-16960?atlOrigin=eyJpIjoiZWRmNm... ) OneToOne lazy loading fails when fetch graph is involved ( https://hibernate.atlassian.net/browse/HHH-16960?atlOrigin=eyJpIjoiZWRmNm... ) Issue Type: Bug Affects Versions: 6.2.6 Assignee: Unassigned Attachments: one-to-one-loading-issue.zip Components: hibernate-core Created: 20/Jul/2023 07:54 AM Environment: Spring-Boot 3.1.1 Priority: Major Reporter: Moritz Becker ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=557058%... ) Given: * Entity with a @OneToOne with a reverse @OneToOne mapping that uses @MapsId * Fetch graph that does not include the @OneToOne association * An entity instance persisted where the @OneToOne is not set. When querying the entity with the fetch graph Hibernate creates a proxy for the association. When the proxy is accessed, the association does not evaluate to null as expected but a EntityNotFoundException is thrown. Find reproducer attached. one-to-one-loading-issue.zip ( https://hibernate.atlassian.net/rest/api/3/attachment/content/50514 ) . ( https://hibernate.atlassian.net/browse/HHH-16960#add-comment?atlOrigin=ey... ) Add Comment ( https://hibernate.atlassian.net/browse/HHH-16960#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#100232- sha1:1e691fe )