I can't seem to unlock the werewolf transformation mastery

I've been trying to unlock the transformation mastery on my werewolf sim but it's not working. Everything else with the werewolves pack is working except for this and I don't know if it's a bug or if I'm doing something wrong. 

I'm playing on a PC with no mods and I've restarted the game a few times so my pc doesn't seem to be the issue. 

I've locked my sim away when they are rampaging and I still can't unlock the ability. My sim is isolated and there are no pets around so I don't know who is catching me.