I own a Santa Fe Caligraphy 2021 since April 2021. For the first 4000 miles, the car was extraordinary, with no issues, not jerky transmission or shuddering. After 4000 miles the transmission started being jerky and the problem not only persists 3000 plus miles later is getting worse. Now it has a very violent shuddering and a lot of other noises and performance issues at low speed. The problem: every time I come to a stop or close to a stop the transmission will change in a matter of seconds 2 gears or at least this is how it feels and sounds. Sometimes it feels like just one shift very rough in any condition. Driving in stop-and-go traffic is nothing but a nightmare. It does it 9 times out of 10 to give you an idea. It's very rare if it does have this behavior. I tried all drive modes and except for the Sport mode, this problem occurs on all of them. Sport mode is the only drive mode where this problem does not manifest, mostly because the car sits at a much higher RPM. The jerkiness, the shaking, the shuddering, and vibrations are so powerful and most of the time loud that the entire car is shaking as you got rear-ended or similar to the transmission having loss bolts and moving back and forth. The minor things as listed in the manual and that are normal about this type of transmission you can feel a slight vibration on the brake pedal or some shifting but those most of the time are not noticeable. It does this only when downshifting and only when are close or already come to a stop. The way it feels I would say from the 3rd to the 1st gear is a mess and transmission has no idea what is doing or is something bad with this transmission. The clunking noise that is also very loud and the shake of the car is being felt by all passengers is nothing normal or not noticeable about it. A lot of time the transmission is shifting the lower gears after I stop the car. This is so dangerous because if I do not seriously keep the foot on the brake pedal the car will move forward, that’s how powerful the **** and the shake of the car are. A lot of times I am just wondering how long it will take until this car will drop the transmission in the middle of the road. The dealer verified the car and they acknowledge that it does all these but they said is normal. Is nothing normal about such behavior in any car and with any transmission. Now at over 8000 miles these symptoms just got worse and it does the same loud and violent ‘’boom sound’’ even when I am backing up from the parking lot in R and the original symptoms just got even louder and more violent/roughness. I am not going to accept an answer like is normal or a defect doesn’t manifest. There seems to be very usual used by manufacturers when no check engine light is on or any other very visible issues. I also tried to sell it but when I went to get the car appraised, the very first stop when test drives it, I've been asked what is with this shuddering. Unless Hyundai bothers to fix this issue, I am left with option one get about 4000$ less in trade because they will take it to auction because no one will buy it after they test it, or option two lemon law and buyback from manufacture. I am gathering documents and following lemon law procedure at this time, just in case I do need to go this route. Except this the car is exceptional. Hyundai seems to still have issues even with engines or transmissions, quality is not there.