Not sure how to reproduce this sadly, but I had made a simple setup that used funnels and belts to take blocks of redstone (example item) and put them into a basin. For whatever reason, the funnel that was supposed to pull from the chest and place onto the belt would simply not work. I recreated the exact same setup nearby, and it worked fine. I tore down the original and rebuilt it, and suddenly it worked. Any idea what might have happened?

Sorry, disregard, pretty sure I had accidentally toggled it with a lever.