This is a HUGE help to me. I'm the shop foreman at a Kia dealership, and i'm dealing with a 2019 Stinger with this same issue in the audio clip. There Is no relevant information through Kias service information, or bulletins addressing this. Previous techs have replaced the amp, and head unit trying to fix this problem, and it didn't correct it. That's why i'm involved in the vehicle. i've been through nearly everything on this trying to track down this issue, from checking all ground lugs, and cleaning, removing components down the line trying to find what affects the concern, disconnected all the speakers one by one trying to isolate an intermittenly shorted speaker, disconnected, and bypassed both DC/DC converters, and have found myself at a loss. I'm currently on my lunch break researching this issue, and i ran across your post, and this makes perfect sense. I'm going to dig into this after lunch, but man, you have no idea how much this one post helped me. I knew this couldn't be a one off issue. Thank you so much for sharing this.