Transmission is not smooth as it its either faster or slower than the engines speed the gear shift timing is not sync with the engine speed and its jerks when slowing down or increasing the speed at lower speed
well, being it is new and under warranty I suggest you bring it back to the dealer.
That’s a pretty common comment when folks switch from a car w/conventional automatic to CVT. Does your new Kia have a CVT transmission? Sometimes the complaint is more about how it sounds than what it actually does, sometimes the complain is that it sounds like a racing car.
A quick web search says it has an 8 speed dual-clutch transmission. Folks sometimes complain about the way they behave, i.e., jerking, hesitation, delayed shifting, etc. That may be the case in this instance.
Ford’s dual clutch transmission has certainly received a lot of attention, symptoms could be related, don’t know.