when using the single argument teleport command (/tp <player>) the teleportation will go to the wrong world if the other player is not in the same world. (e. g. nether / end)
i attached a plugin in that i have used PlayerTeleportEvent to show the e.getTo() location data to make it more visivle.
to reproduce this bug: have 2 players on the server in two diffierent worlds. let one player use the command /tp <otherplayer> (remove any existing plugins that override teleportation like essentials)