Thralls not working at their station?

Hi all, I've only been playing Conan Exiles for 2 days now so I might be doing something wrong. I captured and broke a tanner thrall and have a tanner set up with hide and bark in it. I put them in the world and chose move and guard and it shows them up against the tanner as if they will work. I place them in the world and they stand there for a second in the working position and then just walk off to stand by the fire. When I look in the work station it says the name of the tanner and I can click itt and it puts a yellow border around their name but if I leave the station and enter again it's no longer highlighted. The tanner just stands by the fire 24/7 and doesn't work. Am I doing something wrong?