Blocks don't render when placed inside a empty chunk until reloading them with F3+a
Step to reproduce: Create or load a world, leave the area you joined the world by 3~4 chunks, take any block and build a tower until you find a chunk with no block inside.
Not every empty chunks don't render blocks but they are numerous so it's easy to find one.
Empty chunks are just entirely broken in this snapshot. They seem to behave almost identically to how chunk errors worked in 1.8.