Twilight Strand Full Clear Onslaught Issue

Has anyone been able to fully clear Twilight Strand (normal) on Onslaught? I've run it twice now, and each time after I've killed Hillock I've gone back to fully clear the zone. When there are no more monsters, /remaining has said there are 2 and 1 monsters remaining. Is this an issue or is it just me? Cheers.