2023 Ssangyong Rexton rexton 2023 smokes

Hi, i bought and brand new 2023 Ssangyong rexton, and when i accelerate it, i can see the smoke in the mirror, and when i am parking and i need some gas in reverse, i can see black smoke, i took the car to the Service center, they say that it is soot, and that the vehicle has no emissions, that when I give it gas to move forward with force, it will throw out the soot that is in the muffle, but in any acceleration I can see dark smoke coming out , however I do not see the same behavior in other diesel vehicles, also, they tried the same thing on other brand new rextons and it is the same, looks like thats the behavoior on that particular car, but i am trying to find a solution to this or if it is "normal" , that much smoke strikes me, and if it is soot, how often would it be coming out of the muffle ?