I have a new 2023 Duramax and have had the same problem. The Truck has been in shop twice, replaced the fan clutch both times. The first "fix" did nothing. The second "fix" has resolved the noise at idle, but i still get the noise when engaging the accelerator at low speeds in the morning after startup. Super annoying. I just pinged the dealer again and GM's only recommended repair is replacing the fan clutch. Just how many fan clutches do i have to get replaced in order to have a properly functioning $80K truck?
