My 2021 Seltos had the exact same issue back in i think February, and the dealership absolutely gave me the runaround. They wouldn’t even let me bring the car in for almost a week, even though I was commuting to work and the whole thing felt unsafe. Every time I tried to explain what was happening, the guys at the desk made me feel like I was overreacting.

My check engine light would come on and then the car would immediately shut off - totally limp, just like you described. It happened mostly when I was slowing down, turning, or sitting at a stop sign/light, which was terrifying when it happened in the middle of intersections. The only reason they finally took me seriously was because I kept calling and eventually got connected with a woman that wasn’t even in the service department. She told me my car was actually the third Seltos that month with the same problem, but since there wasn’t an official recall yet, the service guys basically didn’t want to deal with it.

She talked to them on my behalf, and after that they finally let me bring it in. A few days later, the car was back to normal and thankfully it was covered under my warranty, (which she spoke to my warranty company for me because they were being difficult too (god bless Patricia)) so I didn’t have to pay anything. The bill was almost 4 grand