In the presence of a modifying addon, the affected Nether biomes will generate as all stone

I have noticed something about the Nether that would appear to be a bug in the generation algorithm where it doesn’t know what to do but generate as nothing but stone, and occasional Dripstone/Stalactite/Stalagmite cluster and mushroom patches being the only resources making themselves present, specifically in the event that the Nether is loaded with an addon that is modifying the already existing biomes block palette, in which case it trips out and causes the affected biomes to generate as mentioned above. If stone is intentionally added to the block pallet (for instance as the foundation material), even if the addon is capable of distributing them, the resources typically found within stone in Natural, working-as-intended generation, will outright refuse to show up.

 
How to replicate:

1. Create an addon that modified the block pallet of any Nether biome (preferably all, to ensure that when you load up the Nether, you will be guaranteed to see the actual result).

2. Import the addon with the modified Nether Biomes into Minecraft.

3. Create a world with the addon enabled. Turn on “Creation of Custom Biomes”.

4. Go into Creative Mode, build a Nether Portal and load up the Nether.

5. If all biomes block palettes were modified, simply take a look around. If you only modified one or a couple, explore until you find a part of The Nether that is generating entirely as stone with none of the resources you’d expect to find in stone.

Expected Results:

• The affected biomes should generate as the addon specifies. If stone is present in the new block palette and the modifying addon is capable of doing so, ores, dirt/gravel and Granite, Diorite and Andesite should be generating.

• Anything that the addon has added and specified to generate within the modified biomes, should, in theory, generate.

Actual results:

• The block palettes of the biomes modified by the addon are completely replaced by a biome made almost entirely of stone.

• The only resources that generate are mushrooms, dripstone, stalactites and stalagmites, and (in the presence of generated structures) Blackstone and it’s variants, gold, basalt and polished basalt, Nether Brick, and abysmal amounts of soulsand, Nether Wart and the chests and their contents.

• In most cases, all instances of lava or newly introduced liquid by the addon, are entirely replaced by water. Despite this, Stalactites will drip lava instead of the water replacing the lava or newly added liquid.

In a prior version (one of the 1.16 bug fix updates), this was working as intended, as my results from an addon I had made at the time for testing purposes was generating the Nether in the anticipated block palette. I tried it with a different addon in a later version (both Addons revamped ALL of the biomes) only to be greeted with each biome being completely made entirely out of stone, and a result, completely indistinguishable from one another. I would like this to at least be attended to in the near future, thank you very kindly for reading.