I have an ICA4+ but haven’t had the issue you’re describing. A long shot but… Is it possible you’ve created a feedback loop with your audio routing? That can sound similar to what you’re describing. Obviously if you’re using factory settings after a reset/reboot then this possibility is ruled out, but I thought I’d mention it in case you keep reloading the same faulty user preset directly after resetting each time. I had a similar issue with another device recently and I was pulling my hair out until I figured it out… I hope it’s an easy fix for you.