Hear the Waypoint sound when entering a new zone sometimes

I'm assuming this is a bug. The noise that happens when you first activate a waypoint sometimes plays when you use a waypoint and enter a new zone, usually not, but sometimes.

I'm guessing it either never should or always should (hopefully never)

I noticed that too. The sound plays sometimes, sometimes it doesn't.
I personally like it and don't have anything against having it play every time.