When I create a subgraph on an attribute with the ON clause, the SQL join is duplicated, in the next example the table orderPosition is duplicated.

This is on purpose. Hibernate 5 did the wrong thing here and reused the SQL join for a fetch, even though it was not safe to do so, because of the ON predicate.

If you want to filter the elements of a fetched collection, you will have to use a filter.

Closing this issue as rejected.