i constantly use autopilot on trips since we got our 2016 MX. In past 2 months, had several 350+ mile / 7 hr drives. Beautiful sunny day, light traffic on interstate, car clean, no priorissues. After checking mirrors and camera, decided to shift left towards leftmost lane, near concrete barrier. Turn on signal, blue lines never go to dash, or do so for an instant, then back solid going straight ahead. Repeated many times. Same result even from far right hand lane. Right change lanes normal. I took video, and did Bug Report, and called Tesla. Concerned about safety. Seems like at start of trip it worked normally. Couple of weeks later received call from Tesla engineer, confirming they reviewed data, and lack of left lane change. Said something like the system sees a phantom image on that side, but only on autopilot at point of turn signal request. Asked me to schedule SC inspection and review case file. Had to wait until returning from a second trip with the same issues. Naturally SC drives on freeway and it never acts up. Anyone else out there seen this behavior?