This is happening to me too, in a fresh save file. So far Agnes is the only duplicate I've seen, the others just have randomly generated townies in with their NPC label (i.e. Kim Goldbloom is manning her booth while a 'Grocery Store Owner' June Kruse is wandering around the pub). The same random townie replacement is happening with the RoM sages, too. I tried deleting the random sim, but it almost immediately respawned the same one.
One difference, though, is that I don't have the errands show up at all. There's no option in any of the social menus. The only exception I've seen is on Agatha, when the option randomly showed up on the initial social menu when I clicked on her.
Edit to add that Edith (L&D) is now a random adult man? Who is not even a ghost? I am so frustrated.
