Lucky16

Hey new to the forum. I have searched and can't seem to find what I'm looking for. I have a 2015 Silverado Z71 LTZ and my right hand mirror turn signal ihas stopped working. Everything else works just fine (adjusting, flipping them in, and the puddle light). What would cause this? bad wire? or the led light gone out? I would rule out bad fuse since the mirror works in every way except the turn signal part and all other signals work correctly. No bulbs out elsewhere on the truck.