Not much info but I did find this.
TSB Number: SSM 49953 NHTSA Number: 10199506 TSB Date: July 12, 2021 Date Added to File: August 2, 2021 Failing Component: Engine And Engine Cooling Summary: Some 2021 explorer st and aviator vehicles may exhibit a customer concern of undesirable powertrain sounds inside the vehicle and/or less than optimal speaker sound from the vehicle. This may be due to the engine sound enhancement (ese) on