Minecraft wiki entry for Development_versions, associated text: MC-245772 – Outdated chests' loot tables get deleted when updating to 1.18.1.
MC-245817 – Server constantly writes to disk at about 500kB/s.
MC-245910 – Campfires and hoppers cause constant chunk saving.
MC-247636 – Deleting a world no longer logs that a world is being deleted.
MC-248163 – Horrible server performance since changes to auto-saving in 1.18-pre6.