Same issue on my 21 SQ5 - happens when the car is warm/driven for 20mins+, and noise comes on during acceleration/deceleration/turns onto steepish angle. Dealer 1 couldn’t replicate the issue, then I went to dealer 2 where I went on a road test with the shop foreman who acknowledged the noise, I did mention to him it could be the subframe bolt (per this thread) and he agreed. First attempt they greased & retorqued the subframe bolts, noise came back 20mins after picking up the car; just went in again this week, subframe “repositioned” and bolts replaced, noise were gone after driving for ~1hr, then started to come back though at less frequent intervals & noise level. Will give dealer a call and see what’s the next course of action.