I started up a world, and noticed there was a partially submerged cave nearby. I noticed that the water was not flowing down into the cave. I took a look, and noticed that the water was floating over the edge of the cave and not falling.
I started up a world, and noticed there was a partially submerged cave nearby. I noticed that the water was not flowing down into the cave. I took a look, and noticed that the water was floating over the edge of the cave and not falling.
This is because blocks need an update. When they are generated, they don't update on their own. Much like "primed falling sand" needs a block update before it falls.
This is not a bug. This is a way to prevent the client from freezing by scheduling block updates for every generated block in a chunk.