FallingSand and Cactus

When using

/summon FallingSand ~ ~4 ~3 {Block:cactus,Time:1,HurtEntities:1}

To try and make a 3 tall cactus, It only makes a 1 tall one, which will kill the falling sand entity before it places a block, or cannot place a block for some other reason.

Copy the above command and run it 3 times to reproduce.