I am having problems where my automatic item sorter sometimes misconfigures, this did not happen in the vanilla world offline only after I imported this world into spigot I started to have problem, this seems to have some relation to the redstone torch that blocks the hopper going off, the problem occurs randomly and as I said the only explanation would be the redstone torch going off even though I putting 64 items in the first slot and leaving the others filled with stick or snowball system does not break!