Renault Symbol Transmission Failure

Greetings, recently bought a 2008 Renault Symbol with automatic gearbox, the mileage of this vehicle is 25000km and is in very good condition but it has a strange behavior in the change of speeds when it decreases, when the car is accelerated and a speed is already perfect but when it almost stops completely, for example in some traffic light, the box makes a very abrupt change when it cuts and when it is accelerated again and when it is again perfect and when it is the time it is possible to And what can I do to repair it? I really appreciate your help.

Good evening friend, I tell you that I had a 2006 frog symbol but synchronous and I leave my broken pockets, the engine is 1.6V, what I can recommend is that you take your vehicle to the concessionaire or a mechanic specialized in Renault, because the minimum valve has to see a lot with the air conditioning compressor and the velocimeter sensor of the box also has to do with èl, what I want to imply is that if the minimum valve this defective one could be the one that is producing the failure because the engine revolutionizes you too much and when stopping the vehicle presents that pounding.