Picked up a 30mm Sigma "renewed" from Amazon. I'm going to send it back because the copy had this weird issue, but I'm checking to see what could be causing it.

I pointed it at a backlit subject, and the face was a little washed out, but across the washed out are about 2-3 dozen thin green stripes, like it was reflecting the camera sensor. I've tried googling it, but couldn't find anything and because of privacy reasons, I can't upload the example, but I haven't had this issue with either of the two lenses I have (kit and 56mm) when I've done subjects backlit by a bright light source like the sun.

Anyone ever come across something like that?