That all describes what is happening with my 2021. It seems to have started at about 3,000 miles as I never noticed it from day one as others have. It is a bit erratic but very annoying. Sometimes it does it, other times not. But describing it as a distant artillery barrage is spot on for what I have. Too bad there is no way to disable the ANC without disabling the radio. Today I tried just muting the radio to see if that would stop it. I did not hear it after I did that, but I was only about 1/4 mile from home at the time so not a good enough test yet. I don't really understand how ANC works and why there would even be a thumping sound.
Anyone know how it senses a window down so it turns ANC off? I assume it is not just the wind noise of opening the window that does it, but that the ANC senses the opened window electronically somehow? If simply cracking a window 1/4" kills it, I might try cracking the rear passenger side and then covering it with something to keep the cold and wind noise out.
Oh, and does anyone know if cracking the rear slider window turns it off or if it is only the 4 side windows? I will try that next time I drive the truck to see. If the rear slider opened 1/2 inch turns it off, that would be the easiest solution for now I guess.