Sand,Gravel and Blocks affected by gravity while falling ARE DISAPPEARING

When you put blocks that are affected by falling if there's nothing below them, they DISAPPEAR until they hit the ground

1 block, 10 blocks , 10000 blocks, literally doesn't matter what height are they falling from, it will occur everytime !!! 

So far I've tested on Sand, Red Sand , Gravel , Concrete Powder  and they all do the same thing.

HOW TO REPRODUCE :

Just put a block that is affected by gravity somewhere where it'll fall (down).