Slow-Breaking Sand

Bug:Slow-Breaking Sand
So I Was On My MC Server And I Used World-Edit To Make a beach, So I Used Some Cobwebs. some Cobwebs Went Under A Huge Stack of Sand, i Broke one Piece Of Sand And It Slowly Went Down And Destroyed Itself.
If Any Member Of Mojang Goes On My Server, i Will Show You IP:74.63.245.162:25583