Portal costume transformation; no portal?!

Just as the subject line says, I'm trying to use the Portal transformation for one of my costumes, but there's nothing showing up graphically, besides my the avatar animation of them walking off to the side. I was told by a couple people in an endgame chat that this is a common issue? I've never made a bug report before, so I don't know if I did this right.. or what to expect
So thanks for listening. xD