Renault Symbol Transmission Failure

Hello, I recently bought a 2008 Renault Symbol with an automatic transmission. It has 25,000 km and is in very good condition, but it has a strange behavior when shifting gears as it decelerates. When the car is accelerating and in a certain gear, it shifts perfectly, but when it almost comes to a complete stop, for example at a traffic light, the transmission makes a very abrupt shift when downshifting. When I accelerate again, it's perfect. What could be causing this? And what can I do to fix it? I would greatly appreciate your help.

Good evening, friend. I had a 2006 Renault Symbol, but it was a manual transmission, and it cost me a fortune. I spent a lot of money on it. The engine is a 1.6L. What I can recommend is that you take your vehicle to the dealership or a mechanic who specializes in Renaults, because the idle air control valve is closely related to the air conditioning compressor, and the transmission speedometer sensor is also connected to it. What I'm trying to say is that if the idle air control valve is faulty, it could be causing the problem because it's making the engine rev too high, and when you stop the vehicle, it makes that knocking noise.