I was having an issue where Unity was automatically disabling the CoordinateLabeler script component in the Editor, and it was causing all sorts of problems. Apparently, Unity can do this if it detects a null value on Awake. I fixed it by assigning the isPlaceable bool a starting value (true or false) in the Waypoint script.
Maybe someone more knowledgeable can explain it better. Hope this helps if you are having similar problems!