I think the washer pump has failed. Headlights still spray, but with lights off no pump noise and no liquid to windscreen.
How big a job is replacing the motor, can't find anything about the pump location on an A7.
Typical that I've had this and the Sharkfin gps fail within a month of warranty ending. The latter in going to replace with hockey puck antenna, bought for £5 rather than pay Audi £600!