When you go to spawn, you can lose recently acquired items. I didn't think much of it until I lost a deep dark portal, meaning having to redo hours of cobble mining and losing over half a stack of cobble mining, just because spawn and the others don't seem to like syncing up too often. I have seen other complaints of people losing valuables this way too, and it was too big a loss to ignore. Edit: I made another one. Then I waited a while and used it at spawn. It "works", meanng that it teleports me right above spawn when I use it... Euuuuughhgghhghgh.