When you break any block on top of a border block, the particles act weird.
This happens because the barrier that the border block creates pushes the particles around. MCPE-102286.mp4 I would expected that the particles would be completely unaffected by the border since projectiles are also not affected.

How to reproduce:

1. Place a border block
2. Place any normal block
3. Break it
4. The particles act correctly
5. Place that block on top of the border block

Observed result:
They get pushed around, causing it to look weird.

Expected result:
They wouldn’t get pushed around causing them to not look weird.