Basically I was trying to make an infinitely powered cart with a deployer that placed powered rails next to a deployer that places redstone torches, they each have a hopper into them with a crate full of the right item on top. For some reason sometimes the deployer that is meant to place rails places the torches instead, I've checked and there's no way I put torches in the rail deployer, and when I break the minecart the deployer is holding a powered rail like it's supposed to. Here's an image of my problem, after I broke the cart. As you can see the deployers are meant to be placing rails and instead placed some torches.

hello, this is an intended feature. hoppers or any item transportation block won't work on a contraption, you have to put an item/block filter on each deployer to specify the block they place, and they will take items from any containers attached to the structure.no need for hoppers.