general problems of the 2020 Hyundai Sonata

I own a 2020 Hyundai Sonata. I purchased the car on January this year the miles in the car is 700 miles. A month after the car star giving me problem with break. Somehow the car applies the emergency break by itself and doesn't want to move. When I drive the car suddenly stop by itself and giving me message like: to move the car put your seat belt, lock all the door even when I have my seatbelt and doors are lock the car do that when ever the less I expected. I took the car three time for repair and update and the car give me the same problem. The dealer gave me a loaner another 2020 Sonata and have the same problem. This is a very dangerous issues because if is rainy or snowing. The dealer doesn't find anything wrong with the car when they drive the car. I told them that happen when the lees expected.

Pushed the park button, showed p on the dash indicator, doors then unlocked. When exited vehicle it began rolling backward, park had not engaged slight hill only. This has happened repeatedly. Pushed button to place the car into reverse and the vehicle would not engage or go anywhere.