On Java Edition snapshot, magma blocks generate at the bottom of the underwater caves to provide water bubbles for the players. However, on Bedrock, they don't generate at all. This breaks parity between editions.
Step to Reproduce
1. Create a new world with Caves & Cliffs experimental toggle.
2. Go find an underwater cave.
3. Try to find any magma blocks generating at the bottom of the underwater cave.
Expected Results
You can find some magma blocks generating with bubble columns to provide air bubbles to the players.
Observed Results
No magma blocks generating at the bottom of the underwater cave.
Confirmed