Cranking, but not starting from the first time

I have an issue in my Kia Carens 2014. Sometimes the car is cranking normally but it does not start. When I try several times (3 to5 times), it starts . Then, everything back to normal. the car will run normally and smooth. I face the issue maybe once a month. I had the issue for more then 8 months.

I went to dealer two times. However, they said there is no issue since the issue is not happening every time.

The battery of the car is very good. Perviously, I had an issue. One time I pressed the gas paddle fully and a big heavy white smoke coming out of the exhaust, later, a light smoke coming out that stayed for several hours. I took the car to the dealer they said it need only reprogramming. ( the dealer did not give me any details). the car engine is 2.0L. it has less then 100k km.

The warranty of the car will expire soon, so what could lead the car to this issue?

If you can figure out the no start conditions, ie short trip, long trip, after sitting out in the rain, sitting overnight etc. then you can try to replicate the situation and leave it at the dealer so they can replicate the no start condition. Example, sometimes the van would not start after a short trip, got it towed to the dealer 2 times and it started right up. Had the wife stop at the dealer every time she drove by, and the dealer was willing to hop right out and look at it in a no start condition. 3rd time wifey stopped by no start, they hopped on it and determined it was a bad fuel pump. Good Luck to you!