Since 1.9, driving any wheeled vehicle on our dedicated server is choppy. When the car gets a little airtime on bumpy ground (a rough field, a dirt track), it stutters and snaps when it lands, like a desync. My frame rate is fine: the client holds a steady 60+ FPS and the server holds 60 FPS the whole time. Helicopters on the same server fly smoothly, just like on 1.8.