The contact owns a 2021 Ford Ranger. The contact stated that while driving at various speeds, the vehicle hesitated and jerked while depressing the accelerator pedal. The contact stated that the transmission unexpectedly downshifted before slamming into gear. There were no warning lights illuminated. The vehicle was taken to the dealer; however, the vehicle was not diagnosed or repaired. The contact was informed by the dealer to call the manufacturer for assistance. The manufacturer was notified of the failure, and the contact was referred to the NHTSA Hotline for assistance. The failure mileage was approximately 59,000.