Some elements do have the same crafting recipe! And some that exist in older versions don`t exist anymore.

Could you give me a list of which recipes are problematic please?

Seems related to #149

Are there any other recipes? Or only that one?

I will have a look, but I also have Techemistry installed so some otherwise broken recipes may be added by that. However, I do notice duplicate recipes from that mod as well (IE redundant and often worse ways to make compounds outside of the combiner).

That is somewhat intentional. Both mods are allowed to be standalone and currently there are no conditional recipes based on if the other mod is installed, nor do I specifically have plans to do so.

Well this is the only mod i use with chemistry and i tried making vanilla items but another was coming out. When i remember correct it was with slime or eggs, so there might be a lot of other items that don`t work correctly. Oh and sugar has no recipe.

Slime has a recipe.

Eggs and sugar don't but sugarcane does.

Milk can be made but not decomposed (as I said earlier).

Redstone and glowstone only have block recipes not dust recipes.

Netherwart has no recipe.

I added recipes for all the things listed in the last comment in 1.16.4-1, thank you. I have not figured out how to use fluid tags yet, so #149 will remain open