2021 KIA SEDONA Vehicle Speed Control Problems

We purchased a brand-new 2021 Kia Sedona in 2021. Since January, we’ve been experiencing an intermittent but serious issue where the vehicle refuses to accelerate or shift beyond a certain point. This issue has put us in dangerous situations multiple times. One incident occurred while crossing a fast-moving, single-lane road—our vehicle would not accelerate to the appropriate speed, placing us at serious risk. On another occasion, while merging onto a highway, the car failed to accelerate, and we feared being rear-ended due to our inability to keep up with traffic. There are no warning lights or error messages to indicate a problem when this occurs. The only temporary solution has been to pull over, turn the car off, and restart it. After doing this, the vehicle functions normally for a few days, weeks, or even months before the issue reoccurs. We have taken the vehicle to our local Kia dealership,...

DATE OF INCIDENT: 22 APR 2021, THURSDAY DESCRIPTION OF INCIDENT: WHILE DRIVING ON CRUISE CONTROL AT 45 MPH ON A WELL-PAVED TWO-LANE ROAD WITH NO OTHER VEHICLES OR OBSTACLES PRESENT IN EITHER LANE, THE VEHICLE SUDDENLY AUTOMATICALLY DECELERATED SHARPLY, CAUSING THE FRONT END TO PLUNGE. SIMULTANEOUSLY, SEVERAL ALERTS, BOTH IN WORDS AND SYMBOLS FLASHED ON THE DASH. THESE INCLUDED 'CHECK COLLISION ALERT' AND LIGHTS SHOWING A SKIDDING VEHICLE AND A SECOND SHOWING THE FRONT OF A VEHICLE IN A CRASH. ALTERNATING MY ATTENTION BETWEEN THE ALERTS/MESSAGES ON THE DASH AND DRIVING THE VEHICLE, I STEERED TO THE SIDE OF THE ROAD AND STOPPED. THE ENGINE WAS TURNED OFF AND THEN RESTARTED. ALL ALERTS AND SYMBOLS WERE EXTINGUISHED. AN INSPECTION OF THE FRONT OF THE VEHICLE SHOWED NOTHING COVERING OR OBSTRUCTING ANY PORTION OF THE VEHICLE. I ACCELERATED BACK ONTO THE ROAD AND RETURNED TO A SPEED OF 45 MPH WITHOUT...