I was going off what the vanilla unlock looked like. There is no <passive_effect> in the vanilla code. I will give it a try, but the <unlock_entry> is and extended branch of the <display_entry> line.
Are you perhaps saying, the <unlock_entry> only adds the icons to the skill window, and I need the <passive_effect> in the main <effect_group> branch to do the actual unlocking? This is why I hate the xml code for this game.... every mod I look at for code examples is different, and none of them are doing exactly what I am looking for. Thanks for the suggestion. I will try it.
Also the Animal fat is another recipe that I added. It's required for a lot of recipes I am implementing. The modlet my firends and I made reduces the meat requirements for all of the recipes in the game, and greatly reduces the amount of meat you get from animals. It's just a QOL mod that my friends and I play with. It's not something we are considering releasing, because it is kind of a Frankenstein's Monster of various mods patch worked together. I am just updating it for A21 and was having trouble with this one piece. There are other recipes that I was having this same problem with as well, like Dye crafting, and recipes to make canned food. I was just using the corn dog recipe as an example, because all of the entries are pretty much the same.