When SubselectFetch are initialized in the constructor of org.hibernate.loader.collection.SubselectCollectionLoader, the queryParameters.getRowSelection() is ignored.

So when the method loadCollectionSubselect is called on this instance, a new QueryParameters is instantiated, whitout this selection :
new QueryParameters( parameterTypes, parameterValues, namedParameters, ids )

Maybe, the rowSelection should be store as "namedParameters, types, values" ..., or maybe the original QueryParameters should be kept or cloned.