Differential Unit problems of the 2019 Ford Expedition

The contact owns a 2019 Ford Expedition the contact stated that while driving there was vibration in the front differential. The vehicle felt like it was in 4wd when in was actually in 2wd. There were no warning indicator lights illuminated. While driving approximately 30-35 mph there was a vibration and shimmy in the steering wheel the vehicle was taken to the local dealer in July 2021 where it was diagnosed the failure was due to the front differential the vehicle was repaired but the failure recurred. The manufacturer was contacted and referred him to NHTSA. The failure mileage was approximately 47,000.