lethal grove
It could have just been a one-off or because I had my base mounted on a rotating anchor, but my buddy delivered a load of titanite and carbius ore which the base refined and proceeded to deliver to their respective (filtered) silos.
For some reason, the items kept... Falling off the silo and conveyor belts. It seemed like the order of the silo grabbing them was messed up, which led to them continuously falling off after bumping into each other, like a fountain of refined ores. The base wasn't being moved during this.
This is somewhat related and probably not a bug, but a similar thing was happening on a large build I have where it collects ores it mines, refines them, then they move immediately to a mobile delivery cannon. Even though they'd only move one tile, the refined ores fell off and back onto the collectors.