Grass is floating in the air.

There is grass floating in the air.

What I expected to happen was...:
The grass should be on a grass block.

What actually happened was...:
The grass is floating in the air.

Steps to Reproduce:
1. Put in the seed -2566873526468659275.
2. The grass is on the mountain with the small cave, lava pit, pond, and river near spawn.