Dried Ghast spawns even with "Drop 2 2025" experiment disabled

Steps to reproduce:

1. Create a new world. As far as I can tell, most settings don’t matter. The bug does occur with default world settings except for the game mode being creative. Ensure you do not have the “Drop 2 2025” experiment enabled.

2. Enter the Nether, and find a Soul Sand Valley.

3. Find a Nether Fossil.

4. If the Nether Fossil did not spawn with a Dried Ghast, repeat step 4 until you find one that does.

Expected Result:

You will not find any Dried Ghasts at all; all Nether Fossils will only have bone blocks.

Actual Result:

Dried Ghasts will generate in some Nether Fossils, with the correct model but using the “?” texture. They are entirely nonfunctional and cannot be obtained by mining or the Pick Block key. Upon reloading the world, they may lose the custom model and then be able to be picked with the Pick Block key, in which case they appear as the default unknown block, with the name “Unknown”. Regardless, if the world is reloaded after enabling “Drop 2 2025”, all Dried Ghasts in the world and the player’s inventory turn into their normal state.