Hello...I have this same noise in my Niro EV (delivered May 2019 Canada). It is intermittent. It is usually after a longer drive - about 100+KM. I started hearing it at about 2500KM. Kia Service Centre is unable to duplicate and KIA Canada had said there was no known issue. I brought in information form this forum so the technician would know that this has been diagnosed and resolved in France.
On 17 September 2019 KIA Canada informed my dealership similar issue was registered in Quebec. At that service centre, the technicians were able to duplicate the sound.
I think I saw someone on this forum from Quebec. If so, could you post your results and the feedback from KIA? I'm not getting satisfactory responses from my local dealership.
Thank you!