Probably not related to 8.1, but it likes white lines waaaay better than yellow lines. In fact, if I'm in the fast lane next to the carpool lane, it will use the white line that is inside the carpool lane instead of one of the double-double yellow lines on the outer side of the carpool lane. As a result, it tries to keep the car driving basically on top of the yellow lines in thus scenario. If I'm in the carpool lane and the left line is yellow, it had a lot of trouble acquiring that lane marker.
There's a thread on "nudging" the steering wheel while on autosteer. In general I can nudge a slight amount and still keep autosteer active. However, I've noticed that if it loses a lane marker on one side and just has 1 lane marker acquired, then I can nudge it to a much larger degree and move the steering wheel a lot more than if it has both lane lines. Prob not a 8.1 thing, but I just noticed it now because I keep losing lane markers more often.