Funny you should say that. I've been experiencing the exact same thing.
Car is very new, no alignment problems, and the left-side bias is huge. And, it always happens (100% repeatable) in the same spots on certain roads. In other places it is fine.
The dash display shows the car hitting the left lane line, the wheel will vibrate with the lane departure warning, and the side sensors light up red as it almost grinds me into the divider! So the car "knows" what it's doing is wrong in three different ways, yet autopilot is super determined to do it, and keep doing it, anyway.
Something in the motion control side?
This problem is new with 2018.4+ for me.