Clunking on take off

I was just wondering if this is normal? When I shift into gear and start to press the throttle to go I get a hard clunk and then it takes off. It happens when I put it into high gear and then into reverse. Took it to the dealer and they said it was the clutches grabbing the belt. But it just doesn’t seem right to me. So has any body delt with this? i am afraid something might break. This is my first rzr so I am new to all this. Thanks