Magma blocks can generate within ocean monuments

The Bug:

Magma blocks can generate within ocean monuments.

Here is an example:

Seed: 1428380131082779128
Coordinates: /execute in minecraft:overworld run tp @s 47755.49 40.00 62472.88 -155.70 27.60

Steps to Reproduce:

1. Generate a world with the seed provided above and teleport to the given coordinates.
2. Look closely at the nearby magma blocks.
3. Take note as to whether or not magma blocks can generate within ocean monuments.

Observed Behavior:

Magma blocks can generate within ocean monuments.

Expected Behavior:

Magma blocks would not be able to generate within ocean monuments.