I realize this may be a bit late, but the drone gets teleported to the players location when you teleport them. This recently happened to a player on my server, their coords were (-70, -9500, 660) for the drone under listents.
TeleportPlayer playerEntID x y z
that command worked, just use listents and teleport the PLAYER to their current location and bam, drone should be beside them.
Please note that I said teleport the player PLAYER and NOT the drone. Just for clarification.