I used Catnip to get Androgyny and then changed the face so as not to lose the Muzzled flag but lost the perk.
I am thinking there must be some other condition besides losing Muzzled but don't know.
This one is weird. Doing some testing, I got Androgyny with a Human face and was able to keep it.
Changing to Vulpine with the Console also lets me keep it. Using Foxfire removes it, even if the face is already Vulpine.
