It's not surprising that Phelps is not on the list, you're grouping by ?human and he is not... jk, maybe there is an ontology issue i.e. new triples are using a

It's not surprising that Phelps is not on the list, you're grouping by ?human and he is not... jk, maybe there is an ontology issue i.e. new triples are using a different class or that triple-store is not up to date.