It's probably the auto-high-beams, which is one of the sub-par driver aid implementations on Teslas currently (along with auto wipers, and 'smart driver safety

It's probably the auto-high-beams, which is one of the sub-par driver aid implementations on Teslas currently (along with auto wipers, and 'smart driver safety features' that regularly get alarmed --and shock the driver with loud alarm noises-- during totally safe driving.) I haven't paid too much attention, but I believe auto-high-beams are turned on when you use autopilot, and then need specifically turning off. I do find that when auto beams are turned on, the car is less inclined to respond to me when I try to operate the lights manually.