Versions

• Minecraft Version: 1.15.2
• Forge Version: 31.1.25
• Mod Version: v7.0.0-pre16

Describe the bug
When putting blinds next to a slab or a stair you can see through the world.

To Reproduce
The steps to reproduce the behavior:

1. Place blinds next to slabs/stairs // EDIT: this also happens with trapdoors
2. Look through blinds

Screenshots
What it looks like through the blinds:

What it looks like on the other side:

Duplicate of #447