When placing a waterlogged block at least one block above a bubble column’s source, the block gets deleted a few ticks later.
Steps to reproduce:
Load a world on the latest snapshot.
Go underwater.
Place a waterloggable block a few blocks above where you will place the column block.
Be sure the block is waterlogged and that there are water source blocks beneath it.
Place Soul Sand or a Magma Block a few blocks beneath the waterlogged block.
Expected result:
The waterlogged block stays and stops the column from continuing upward.
Actual result:
The waterlogged block is deleted from the world.
Reproduced in 26.1-snapshot-4.
This issue seems to have started in 26.1-snapshot-3.