Pet Glitch?

Since you can now put pets in your den, the pet you are currently with lights up green when you go the the pets section when customizing your den. A glitch happened to me while I was redecorating my den.

My welcome mat was glowing green when its not supposed to! I wasn't even using it my den! Heck, when I clicked it it even said what it would usually say if you clicked the pet that was already in use!