That's because you use a tag that is limited to 1, namely, "Drone", combined with "Drone" is not playing.
Perhaps extend it with the UID of the cPlayer.
tag: "Drone" & cPlayer.UID
The first event, would also require the Tag is not playing check below the LOS check.
LOS check cPlayer
tag "Drone" & cPLayer.UID is not playing
play audio with tag "Drone" & cPlayer.UID