To me it appears to have come from elsewhere. I had not updated my drivers in a long while, and just out of nowhere the issue occured. I then updated my drivers, no change. I then went even further back driver wise than the original driver I had and the issue got "semi fixed" in that as long as I didn't tab out, the robes and cloaks didn't vanish. Might it be something to do with the new CEP update?
I'm now currently running the new drivers, and as soon as I log in I have to change my resolution ingame down, and then back to normal to fix the issue. And I have to do it every time I tab out as well.