Terra Flex 3" lift?

First off I'm new to this forum. I hope I can contribute in the future. My question is about my 14 wrangler unlimited. I had the dealership install the terra flex 3" lift with fox shocks riding on stock 18" wheels and 35" terra grapplers. The ride is good but driving it is almost nightmare-ish. It wanders and floats all over the road. Any road imperfections make it crazy to stay on track. The dealership said its normal. I've driven too many lifted trucks to know it's not normal. Anything I'm missing? Or suggestions? My wife won't drive it on the highway cuz it scares her.

Thanks in advance