I've only heard a kind of whisper noise, nothing that could be described as a "klank or cracking noise". If you hear this sound when decelerating,I'd be inclined to get it checked out - it might indicate something loose or broken in the brake hardware, and that could become dangerous. If you hear this sound when accelerating from a stop, it might be related to the hill-stop-assist logic that is designed to hold the brakes momentarily when you are stopped on a steep hill. If you think that's what it is, you might ask yourself if you maybe have a habit of pushing significantly harder on the brake pedal than is necessary when you are fully stopped. Try using a light touch and see if you still hear that sound, or not.
2018 Niro PHEV Gravity Blue