3rd brake light ?

I've noticed that my center led light is not as bright. Since I only drive my truck I've noticed it in my security cams. When I get out and look it's brighter at different angles but dimmer looking straight behind. I saw another raptor in traffic today. It looked different than mine. All three leds were bright. Any ideas. Do I have the correct lens? Thanks.

looks like its dying.. take it in to the dealership.