Adaptive Cruise Control problems of the 2017 Kia Motor Optima

I was driving with an SUV in front of me at 18-wheeler in front of them. This is on a road where the speed limit is 65 however there's a section on 301 where there's a traffic light. All three vehicles came to a slow normal stop and the adaptive cruise control was doing a good job of slowing the vehicle down without my input. But the SUV when we were at about stopping speed but had not yet come to a complete stop, the SUV switched to the left lane. At which point I was maybe 20 ft behind the 18-wheeler and all of a sudden the car is adaptive cruise control tried to accelerate the car back up to the setting of 65. It didn't register the 18-wheeler at all it just registered that the car in front of me had cleared the space and if I had not been paying attention and immediately applied the brakes to stop the car manually it absolutely would have accelerated directly into the back of the 18-wheeler. I was maybe 5 ft and it was still accelerating when I slammed on the brakes. I've been able to since reproduce the effects, it doesn't register 18 wheelers correctly in this specific situation as vehicles. I've even had the camera recalibrated in between tests. I have everything on video but unfortunately do not have access to the car's computer logs. I would be willing to send in my ecu for whatever is needed to identify this further.

On 6 June 2022 I was driving eastbound interstate 80 passing fairfield, CA. Traffic was moderate, average traffic speed 65. The kia’s adaptive cruise was enabled and set to the maximum amount of safe distance. I recall the car directly in front of me changed lanes to pass a truck towing a trailer. I remember the kia began to accelerate and I couldn’t turn the wheel. Next memory was opening my eyes to the dust smoke of deployed air bags. I lost consciousness likely due to the sudden impact and air bags deployed. I was taken to a fairfield hospital by ambulance where I spent 4 days. A slurry of tests ruled out loss of consciousness as the cause. No stroke, heart attack or seizure occurred. I was treated for bruised ribs due to the airbag. No doubt to me that this collision could have been catastrophic to this driver and others driving nearby. Witness reported that I sped up and clipped the truck/trailer while attempting to pass. What I believe happened: 1) the adaptive cruise accelerated when it determined there was room but failed to see the trailer and 2) the steering was unresponsive when I attempted to avoid a collision. The reaction time between car accelerating and getting knocked out had to be a mere three or four seconds. The vehicle was totaled, the insurance company, Mercury insurance, released the vehicle.

Cruise control does not maintain a steady speed and constantly fluctuates 10+- miles an hour! the dealer refuses to fix and says they cannot reproduce the symptom. I used a tracker and saw the dealer drive it around the block, never attempting to put it on the freeway.