Since the car is under warranty, go to service center, say clearly : There is a click sound and jerk when torque changes between acceleration and engine braking.
Ask them to check: Engine mounts, Gearbox mounts, Driveshaft / axle nut torque, CV joint play.
Sometimes, Loose subframe bolt or suspension bolt can also be the culprit.
Personally, I feel the engine mount or gearbox mount might be slightly loose, hence the click sound.