Summary:
If you place two pistons with the piston side to the same block, and place an end crystal on this block, and then activate the pistons by placing a redstone block between them, the pistons will move into each other. Only works in the end world.

Steps to reproduce:

1. Navigate the End world.
2. Place two pistons with the piston side facing the same block.
3. Place 1 height below obsidian or bedrock (on the block where the pistons will be extended).
4. Place on an obsidian or bedrock the End crystal.
5. Activate the pistons by placing a redstone block in the corner of the pistons.

Observed results:
The two pistons moved out at the same time (into each other).

Expected results:
The pistons will not push into each other.

Video:
Minecraft Preview 2022-05-12 11-15-22.mp4

Image: