The contact owns a 2024 Kia EV9. The contact stated while driving at various speeds, the middle-row passengers side seat failed to remain secured. The contact stated that due to the failure the middle row passenger seated in the seat was moving forwards and backwards because the seat failed to remain secured. The contact stated that the dealer nor an independent mechanic was contacted. The vehicle was not taken to a dealer or independent mechanic to be diagnosed or repaired. The manufacturer was not notified of the failure. The failure mileage was 35,701.