Armor stands didn't adapt to snow layers

Steps to Reproduce:

1. Dig a 1 block wide and 8 long pit
2. Put snow layers range from 0-8 levels
3. Put pistons so when they are activated, they will block the light from above it giving shade
4.Activate it, put blocks on top of piston arm, and put armor stands on top of pushed blocks
5. After you deactivated it, you will see that armor stands on snow levels 0-4 adapts like an empty block (0), snow level 5-7 adapts as a slab and 8 adapts as a full block