Minecraft 1.18.1 | AutoRegLib 1.7-52 | Quark 3.0-334

Not a major bug but rather an inconsistency. Normally, you can't put anything made of Crimson and Warped wood as fuel in furnace. However... you can put chests, ladders, and bookshelves made out of those wood types in furnace fuel slot.

Step 1: Give yourself any of the following made from Crimson and Warped: Ladder, Bookshelf, Chest, and Trapped Chest.
Step 2: Access any furnace and right-click any of the above items.
Step 3: Observe that they go into fuel slot. This is inconsistent with how fireproof the Nether Fungus wood types are.

It's a small, easy-to-fix inconsistency.