My sim has a dark form, but never uses it when feeding or using his abilities. Is there a way to set it up so he'll automatically transform or do I have to do this manually each time? Update: so I ...
Maybe try running the repair tool on your game? That seems to fix a lot of weird little issues like that for me. Otherwise, I'm not too sure and you might want to check out EA's bug page: https://answers.ea.com/t5/Bug-Reports/bd-p/The-Sims-4-Bugs and see if it's there? My vampires all change form to feed regardless where they are. :/