Items disappear from bundle when going through hopper system

I have a basic hopper system with chests surrounding a furnace, allowing fuel and materials to funnel into the furnace and out into a chest at the bottom. I accidentally slipped a bundle into a chest at the top which sent the bundle into the hopper. When I checked the hopper to retrieve my bundle, all of the items inside were gone, taking my bucket, ender chest, sculk shriekers and sculk catalysts with it. I retested this with a stick in a bundle while the furnace was inactive and full of coal, and it did the exact same thing. The stick was nowhere to be seen.