I have found myself to have been travelling for some time and thinking it was engaged ... only when car started to drift out of lane, and I found how easy it was for my one-hand-on-wheel to correct it, that I realised. The Icon on the dashboard is completely clear of course ...
I reckon that the half-and-half before we get to full Autonomy will have these sorts of issues
For the first week or so I genuinely thought auto-steer was absolutely cr*p. I enabled through the console and kept drifting towards the lane markings. Even gave some in-laws a demo of the car and quickly glossed over the fact that it couldn’t stay in lane in full autopilot mode.
Then I became aware of the double whack that needs to be performed on the mode selector stick to activate auto steer and eureka!