Attempts to update a lazy object result in the creation of a new object rather than modifying the existing one.

I have a user document that has a reference to subgroups as lazy. I am trying to get a subgroup from the user and then try to modify it but instead of updating it tries to insert a new one. This is only the case when I add the auditing field @Version version. If I removed the version field, everything work fine and it update the document.

       // PostConstruct
	public void test() {
		setup(); // setting update test data
		executeOperation(); 
	}

private void executeOperation() {
	final User user = userRepository.findById("1").get();
	user.getSubTree().getChildren().add(subRepository.findById("p1").get());
	nodeService.save(user.getSubTree());
}

private void setup() {
	final MongoUser user = new MongoUser("1");
	user.setName("test");
	final MongoUser savedUser = userRepository.save(user);
	final MongoSubGroup group = new MongoSubGroup();
	group.setId("BASE");
	group.setOwner(savedUser);
	group.setName("BASE");
	subGroupRepository.save(group);
	
	final Dept mongoDepartment = new MongoDept("dept1");
	final Dept savedDepartment = deptRepository.save(mongoDepartment);
	
	final MongoSub profile = new MongoSub();
	profile.setId("p1");
	profile.setOwner(savedDepartment);
	subRepository.save(profile);
}`

From executeOperation() there is a lazy load operation for subgroups and then there is a call to nodeservice

public void save(SubGroup subgrup) {
		for (SubTreeNode node : subgrup.getChildren()) {
			// skipping Some business logic
			final Link link = new Link();
			link.setId("1");
			((MongoSubGroup) (subgrup)).getLinks().add(link);
		}

		groupRepository.save(subgrup);
	}

So here as soon groupRepository.save(subgrup) tries to create a new one and as id as the index it gives duplicate error

Caused by: com.mongodb.MongoWriteException: Write operation error on server localhost:27017. Write error: WriteError{code=11000, message='E11000 duplicate key error collection: demo.subGroup index: _id_ dup key: { _id: "BASE" }', details={}}.

Attached sample project
demo.zip

Start by running the attached demo project and reproducing the failure in executeOperation(), especially the lazy subgroups access followed by nodeService.save(). Trace groupRepository.save(subgrup) through the @Version handling and lazy object mapping. Done means saving the existing subgroup with id "BASE" updates it instead of attempting a duplicate insert.