I cannot move the custom destination marker to my location, only a distance away. It doesn't work at all on the local map. Is this a bug, how the game meant it, or a problem on my end?

Map marker does not work on Local Map.

It is really to single out a location on your map when you have several quests selected or to remind you to head in certain direction when you are wandering around on your way to a place. I have also noticed that sometimes I can not get it on top of a map location that is marked or is going to be marked.