Blocks are randomly spawning in

So recently I deleted my server's survival world and replaced it with a new one. While a player was exploring we encountered this glitch. This is what the video shows. I have no idea what it could possibly be. The generating structure looks like it could be pieces of what they built in the old world.

The plugins I have installed are:
BetterSleeping3, BuycraftX, ChatFilter, DropHeads, Essentials, EssentialsSpawn, HolographicDisplays, Lobby, LPC, LuckPerms, Multiverse-Core, Multiverse-Inventories, Multiverse-NetherPortals, Multiverse-Portals, MultiverseSpawn, PluginConstructorAPI, ServerAnnouce, SpawnerSilk, TimeMachine, Towny, TownyChat, TownyNameUpdate, TsunamiListener, Vault, Votifer, Worldedit, Worldguard