Plains Village Houses Keep Popping Up in my Custom Village Structure

For whatever reason, houses from the vanilla village just pop up at random during worldgen. I've checked the jigsaw blocks within my structure pieces several times, and my template pools have 0 references to any of the Plains village structures. I don't remember exactly when this started to happen, but it was working just fine until a certain point while adding more nbt files to the pack from my build world.