The contact owns a 2021 Ford F-150. The contact stated while driving 60 MPH, the transmission independently shifted to neutral, and the vehicle decelerated. In addition, the power train failure warning light illuminated. The contact stated that within several seconds, the vehicle returned to normal speed, and the power train failure warning light was no longer illuminated. The contact stated that the failure occurred while driving on a major highway. The vehicle was taken to the dealer where it was diagnosed with an external transmission failure. The contact was informed that the transmission needed to be replaced, and the software needed an update. The vehicle was not repaired. The contact was informed of an unknown recall however, the VIN was not included in the recall. The manufacturer was made aware of the failure but provided no assistance. The contact was advised to contact the NHTSA Hotline to report the failure. The failure mileage was approximately 79,000.