@arikitsuragi Vanilla game is "unmodded game". You need not delete DLCs. Simply, you move whole The Sims 4 folder to desktop, and start new game in condition the EA folder being empty. You can start a new vanilla game. After testing, you can delete the new Sims 4 folder for testing or keep the folder for something. When keep the folder, it would be good to you rename the folder or put in the other named folder, for example played Sim's name.
And about that trait, I'm not sure, sorry. In my data, no sims had that trait. And there is still no report about trait.
