I had a 2011 Kia Optima, same car as the Sonata, that did the same thing. You would let go of the wheel, and the wheel would turn left a little, and the car would pull left very hard. On long drives, your arm would get tired just trying to keep the car on the road.
I brought it back 5 times to the dealership, and the first time I brought it in, the guy said there is definitely something wrong with your car. When they couldn’t fix it, a guy from corporate came and assured me that there was nothing wrong with my car, and then insulted me by saying I haven’t been driving long enough to know how a car is suppose to react to the road. But even if the road banked right, the car would still fight to go left. So I got a lawyer, and ended up suing them and won $9,800, then sold the car for $1,000 less than I paid for it.
I think all of these cars have this problem, and they're trying to keep it under wraps because I was told I was not allowed to talk to my service department about this issue; I had to call the guy from corporate.
If I were you, I would maybe look into it, if it’s as bad as my car was.
Moral of the story: Stop going to dealers if they find nothing wrong with your car. What you should have done after the second trip to the dealer is take it to a competent alignment shop and have it thoroughly looked at. They likely could have solved the problems, and then you can take up the repair bill with your dealer service department after they drive your car, and see that it now goes straight down the road.
In reality, you'd never get anywhere with the dealer, but I would at least send a copy of the bill to them and corporate, letting them know how incompetent they really are, and that the minuscule amount you had to pay out of pocket will likely lead you to a Honda dealer for your next car.