Hello, just got mine 2 months ago (2nd hand 2019 model) and had the same issue. At low speeds (and engine is cold) I could hear some a "rattling" noise.
Dealership says "it is a normal sound as the exhaust has an metal flexible connection and this makes that noise. After it gets to a good engine temperature it should stop".
To be honest, in my case, it really goes almost to a non existing noise when the engine warms up. Although it does not stop 100%.
cheers