The contact owns a 2022 Hyundai Ioniq 5. The contact stated that after the vehicle was parked on a slight incline on the road, the gear shifter was shifted to park(P), and the vehicle was turned off. The contact stated that while exiting the vehicle, the vehicle started to roll backward. The contact was able to jump back into the vehicle and depress the brake pedal to stop the vehicle. The contact stated that the vehicle was still in park(P); however, when the brake pedal was released, the vehicle started rolling away again. The contact had not engaged the parking brake. The contact stated that the vehicle was turned off and restarted and was able to shift into park(P) and the vehicle remained stationary. The contact stated no warning light was illuminated. The contact had not taken the vehicle to a local dealer or independent mechanic. The vehicle was not diagnosed or repaired. The manufacturer was not informed of the failure. The contact researched online and related the failure to NHTSA Campaign Number: 22V324000 (Parking Brake); however, the VIN was not included. The failure mileage was approximately 25,000.