Mine started to smell when AC started up at about 10 months after delivery. The dealer used the Toyota evaporator 2 part cleaner and changed the filter in the glove box. All fixed for now. They did it under warranty.
The Toyota cleaner costs about $20 retail. It's a foam that you inject through the evaporator drain tube, let it sit for about 15 minutes and it changes to a liquide that flushes out the drain tube. Part 2 is a chemical that you spray into the fresh air intake with the fan running on fresh air, not recirculate. .
It kills mold, mildew etc that cause the smell.
Here's a you tube video
Here's a link for the Toyota refresher
I was also advised to run AC on fresh air prior to turning car off which helps recurrence.