Hello all, I come to you with a strange lighting issue that I can't seem to figure out.

When I'm driving with the exterior lights on, everything will work fine but about 5 or 10 minutes in the orange lighting indicator pops up on the dash. Its indicating that a light is out and its always my left tail light. Now I figured it would just be a loose bulb or fuse but here's where it gets tricky. Whenever I press the brakes the brake light(which is the same as the tail light) illuminates. So the bulb must not be out, and I don't think its the fuse for that reason. I have no idea what the issue is or how to fix it. Help?