So far, when riding a white horse(Have not tested other horses), every time when riding, every few minutes or so, my horse would stop automatically walking up one block. Additionally, my player, even off of the horse, becomes boxed in world borders. A temporary fix is to save & quit and rejoin, but it always reoccurs. This is not a multiplayer world. This bug, when I rejoined the world a few times more, randomly spawned me somewhere else and killed me with fall damage, despite me being in an enclosed place previous save.