Vortex saying FNIS Creatures already installed (clean install of Skyrim and Vortex)

[tomtheclone]

Things were going wrong in all kinds of inexplicable ways, so I decided to download and install Vortex, and git it a go. I also make a clean installation of Skyrim LE.

 

I install FNIS okay for the most part, but when I go to install the creature mod it tells me its already installed and wants me to make a variant. I choose cancel, which seems to have installed it. I'm not sure what actually happened, but more importantly, why is Vortex saying the mod is already installed? Is it confusing it with FNIS behaviors?