Lalo

Hello everyone, I have a 3 months old IS250, with a bit over 5000 km on the odometre. My car seems to dislike engaging the 3rd gear, whether I am accelerating or decelerating, and changes quickly from 2nd to 4th, or vice versa. The changes occur smoothly though, but it just does not make sense to me that a car would just skip a gear on Auto mode. Did anyone else have a similar problem? What did you do about it? Thanx