[MC-272117] Sometimes lava generates underwater and doesn't turn into obsidian

Steps to reproduce:

Seed:5058386815178157355

/tp 10 -50 -7

Observed result:

Lava generates underwater and doesn't turn into obsidian.

Expected result:

When lava generates underwater, it always turns into obsidian.

Notes:

This happens since 1.16 or earlier.

Similar to MCPE-140185.

Attachments

Can confirm:

[media]

Would MC-237017 describe your issue? (Note; this is not exclusive to -64 as shown in the duplicate reports)

No. This issue is only for lava can generate underwater without turning into obsidian.

MC-248068 was resolved as a duplicate of MC-237017 which is why I ask. That issue also showcases lava not converting into obsidian as well.

MC-248068 shows a world used datapack to change the cave generation.

But this issue shows a vanilla seed with default world.

And sometimes ruined portal also cause this issue,