why is the auto gearbox slow to pickup after slowing down but not stopping. on 2002 Volvo S80

Once the car is at normal temp,if I slow down for a roundabout but dont stop,then drive round the junction at slow speed, when I accelerate away nothing happens for approx 3 seconds, then it picks up normally.
There is no lurch or roughness, just a delay.
There are no other problems. Car has done 160,000mls.

Asked by for the 2002 Volvo S80
1 answer
review when tranny last serviced. may be due. bring to tranny shop and have them run diagnostic. tranny tech. will advise.