Piston at the world border creates a persistent invisible collision block after world reload

Version: Java Edition (latest release)

Steps to reproduce:

1. Go to the world border.

2. Place a piston one block away from the world border.

3. Place any movable block in front of the piston.

4. Activate the piston so it pushes the block into the world border.

5. Save and reload the world.

Expected result:
The pushed block should behave normally or be removed without leaving any invalid state.

Actual result:
An invisible collision remains at the pushed block's position after reloading the world. The block is not rendered and cannot be detected as a normal block, but it still affects gameplay. The invisible collision can persist across world reloads and can be removed by an explosion.

Additional observations:

• Reproducible with different movable blocks.

• Happens in singleplayer.

• Triggered only at the world border.

• The issue persists after saving and reopening the world.

Additional observations:

• The issue is reproducible in singleplayer using the latest Java Edition.

• It only occurs when a piston pushes a block at the world border.

• The invisible collision persists after saving and reloading the world.

• Explosions remove the invisible collision.

• If the bug is reproduced inside an active Nether portal, the portal animation becomes permanently frozen and the portal sound loops continuously until the invalid collision is removed or the area is unloaded.