"Shaking" falling blocks get broken when reloading the world

The bug

Shaking falling blocks (gravity blocks that turn into a block and back into a falling block over and over again) will break and drop when the world is reloaded. This happens for all types of gravity blocks, like sand and gravel.

To reproduce

1. Build the contraption shown in this screenshot
   (redstone dust goes under both pistons)
   
2. Right-click onto the note block once if you haven't triggered the observer already
3. Place a sand block on top of the pistons against the polished diorite block
4. Close and reopen the world
   → The sand block drops

Original description

I have a sugar cane farm and it gets destroyed everytime I join my world, no matter if I fix it or not, keeps destroying (the sand somehow dissapear so the water goes off destroying redstone)