Discovered while testing MC-244146.

The bug

The pattern formed by bedrock at the bottom of the world seems to always be constant, regardless of the world seed.

This was previously the case on Java Edition, but was intentionally changed in 21w40a (https://www.minecraft.net/en-us/article/minecraft-snapshot-21w40a), making the absence of this effect in Bedrock Edition a parity problem. I also remember it being different in Bedrock Edition from seed to seed in older versions, so I don't know why it's gone to Java's old behaviour.

The two seeds tested were 1 (input as ddnqavbk due to MCPE-44604) and 1736465059.

How to reproduce

1. Generate a world
2. Teleport yourself to (0,-59,0)
3. /fill ~-20 ~ ~-20 ~20 ~3 ~20 air
4. Note the shape of the bedrock pattern - take a screenshot if needed
5. Redo the above steps but generate a different world

Expected results

The shapes formed by bedrock would differ due to the seeds being distinct.

Actual results

The shapes seem identical.