Renee Moreland

I have a 2007 Audi A8 L. I try to put it in dynamic mode but it goes back to automatic . No chech engine light is on still ride great but just want to know why it want go back to dynamic. Could it be that I changed the rims and tire sizes. Idk someone help. It was n dynamics mode for about 2 weeks and it jus started jumping back to automatic today. The dealer said it could be the tires and rims and I would have to put factory back on to get it to ride in dynamic mode.