Working as Designed Cannot use block swap on sand

[SnookieDoodle12]

Steam or GOG

Steam

Single Player/Multiplayer

Multi

Operating System

Windows 8/8.1

Terraria Version

1.4.0.4

Controls Used

Keyboard/Mouse

I was playing multiplayer with friends online and we were building a desert house for our npcs and none of us could use block swap on sand and the sand wouldn't even crack and we had to swap to our pickaxe just to break the blocks. I don't know if this issue is in singleplayer but this issue might affect other blocks like silt or slush.

 

[CoronaKing]

This is intentional, none of the blocks that are affected by gravity (Sand, Silt, etc), can be swapped out.

 

[Xaix]

I think that is because sand is not a static block, it is a dynamic one, since when it have a space under it, it will fall. So this block swap is only for blocks which are placed and stay that way. I might be wrong. Have you tried with silt or slush?

 

[Adapting]

This is intentional, none of the blocks that are affected by gravity (Sand, Silt, etc), can be swapped out.

This and apparently you can swap a regular block with sand, and replace sand with (a different type of) sand. Same for silt/slush, according to @Unit One.