The bug:
Magma blocks generate inside icebergs in frozen ocean biome.

Seed: -6922903877723559230
Coords: /execute in minecraft:overworld run tp @s -67.83 64.74 -247.41 548.76 37.85
/execute in minecraft:overworld run tp @s -21.41 50.49 -316.88 417.34 14.37
(there is also allot of lava pockets in icebergs in this world, i found 3)
Expected result
Magma blocks should generate in water filled caves, they should not replace ice and packed ice.