In my friend's multiplayer world "blö" my friend and i somtimes seeing a place were the chunks not loading in, but we can walk on it and for example breaking a block that are sand, it will drop the visible sand-drop. You can see if there are any space in the underground, its black there, and you can also see mobs on and under the ground. To se the blocks again, you must save and exit and join again, and that is very irritating! 😡

Its the same in my own worlds, also in creative.