[OPEN] [W] 'Transformation Mastery' Ability Not Unlocking

I had this or a related problem once. Most of my werewolves are able to unlock Transformation Mastery when they're alone. But there was one who failed four times in a row, even though he was the only sim on the lot and locked in an empty basement with no access (I teleported him in) during two of these attempts. All the failed tries were during full moon nights. Soon as my sim had a "normal" rampage, he unlocked Transformation Mastery easily.