Hanging Signs not breaking if there is no blocks around

Description :

When an hanging sign is placed on a block, and the block is removed the hanging sign is floating in the air

Reproduction :

Place an hanging sign on a block at least two block upper than the floor level, and then remove the block you placed the sign on. You should see the sign floating in the air.

Expected behavior :

The normal behavior should be to see the hanging sign destroyed instead of floating in the air.