That’s what I assumed, but he was spawning when he was still where he should be. I hadn’t looked at him in cas full edit he ran off and despawned (as he is supposed to) but a new Greg respawned when my sim checked out the signs again.
Kristopher volkov and Rory also spawned twice, Rory was identical but Kristopher had a different surname. So far, no extra Spawns in my new repaired save, and Greg and my sim have a daughter called Genesis, he still lives/appears where he should, I got them into one of the new woohoo bushes!