The contact owns a 2019 Cadillac CT6. The contact stated while driving approximately 50 MPH, the vehicle was lagging. There were no warning lights illuminated. The contact received notification of NHTSA Campaign Number: 25V148000 (Power Train); however, the part to do the recall repair was not yet available. The local dealer was contacted. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The failure mileage was unknown. VIN tool confirms parts not available.