On the screenshot below, you can see that the falling sand on the left stops his fall on the hitbox of the fence, not the fence itself.
So the sand is still a falling sand entity and never become a block again.
MC-126504
Blocks that are affected by gravity fall on blocks hitboxes, not blocks themselves
Resolved
Duplicate
0
Yanis48
(Unassigned)
Unconfirmed
Minecraft 18w09a
Retrieved
Thank you for your report!
However, this issue is a Duplicate of MC-90523.
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