Defogger problems of the 2013 Chrysler 300

Cabin air recirculate stops working. Chrysler says that is normal function. But when you are driving behind a diesel vehicle, you are stuck breathing that air, and it makes me sick. It goes on occasionally, but only for a minute or two. Then it goes off, and you cannot turn it back on. I have driven many miles in many climates and get the same result. I have owned a Chrysler 300 before and it did not function like this. Nor, any other vehicle I have owned.