Mine carts lag/stutter badly

Since last update, mine carts stutter/lag badly. Travel time is much longer than it should be. On level terrain with powered rails every 27th segment, a player can run faster than a cart with a player in it. Problem appears to vary by chunk. Issue noted by all players on realm. Problem is less likely to occur if only one player on realm. Problem may be affected by direction of travel. Problem may get worse if player frequently exits mine cart.