If an anvil drops on slab, it plays the sound of breaking it by smithing

 

What I expected to happen was an anvil falling and breaking without any sound when dropped on slabs, flowers etc.

What actually happened was that it played sound Minecraft:block.anvil.destroy

Steps to Reproduce:
1. Place anvil attleast one block above any non full block like slab, flower etc.
2. As it falls on the slab, It breaks with Minecraft:block.anvil.destroy sound
3. You have seen/heard the bug i was talking about