Editing Terrain after Cloud Level (~y:100)

I edited the Terrain after y:100, closed MineCraft, and loaded up my world again, and everything did just dissapeared.

What I expected to happen was, that everything is still there.
I thought, that the Blocks would be there.

What actually happened was, that all blocks did just dissapeared.

Steps to Reproduce:
1. Build a "Building" over Height y +100
2. Open the menu and press "save and quit to title"
3. Re-load the world, all blocks you buildt should have dissapeared.

Im sorry if i wrote anything wrong