Adaptive Cruise Assist Steering?

[Barrychuckle]

I've taken delivery of a new A8 55TFSI which I'm very pleased with.  

I previously owned a Volvo with Pilot Assist, which had lane assist and pilot assist, lane assist would basically 'kick' the steering so you remained in lane whereas pilot assist gently steered you when adaptive cruise was active.

My understanding was the A8 has the same features albeit by a different name, however when I engage cruise assist, the adaptive cruise works fine, but rather than gently steer me within the lines, it simply kicks me back when the car veers over the line, so effectively the car zigzags in lane.  Clearly this means I cannot rely on the steering feature.

I appreciate this is not the easiest concept to explain but hopefully it makes sense, does anybody with this feature on their Audi find the same, is this a limitation of the car or is mine malfunctioning or more likely I'm not operating it properly?  All the lines on the diagram show green as I know the car needs clear road markings?

Any help would be welcome as I'm really missing my pilot assist! many thanks