Fixed for the next update. Once you leave the zone after he gives you the Juice he gets moved back to the lab, and there he's got a different set of dialogue options. From now on he should be standing next to the rift; if he isn't, simply reentering the zone will reset his position, and you'll get the proper dialog options.
Sorry for the very late response. We had some... covid-related issues recently, but we're alright for now.