Sportsman 1000 Won’t shift while at idle.

I just bought got a new sportsman xp 1000. I have just 3 miles on it.
Pretty
Much just off trailer and around the yard. It will only shift when the atv is off. I have to put in the desired gear while off. Then when I start it, it moves. I have to hold the brake to keep it from moving. The dealer said it will go away. I had a 500,550, and a 800 sportsman and never had this problem. Is this normal for this atv..