I have re-read your post. I have had an 2024 plate Audi S3 that had all the bells and whistles on it. You could let it drive without any intervention very gently steering and all that it would do was sometimes complain that you weren't holding the steering wheel.
Can you display the Driver Assist menu that shows you what it's up to? Mine would show cars in front and to the side. The braking was always uniform and would show you why it was braking. You could set the gap to the car in front. Mine would warn you if you were too close to something.
On a clear road without obstructions is the braking predictable? I hate to suggest this but what was the reason for the car being on sale. I sold mine for logistical reasons rather than any fault with the car.