Blocks can be placed into spawn protection by placing them on blocks with small hitboxes

The Bug:

Blocks can be placed into spawn protection by placing them on blocks with small hitboxes.

Steps to Reproduce:

• Start a server and join it.
• Give operator permissions to yourself.
• Set the world spawn to your current location.
• Locate the edge of spawn protection.
• Place a block with a small hitbox adjacent to the edge of spawn protection. (Pointed Dripstone, Chain, Candle, Fence, etc..)
• Remove your operator permissions.
• Give operator permissions to any person other than yourself.
• Whilst looking at the edge of the block that you just placed, attempt to place another block.
  →  Notice how you are able to place a block in spawn protection, by placing them on blocks with small hitboxes.