Guild Wars 2

After the Halloween update I am constantly experiencing a strange thing with mining nodes.

Mining nodes whether it is copper vein or raw candy corn – all in a sudden disappear when I get closer and there is no visible depleted node. No chance to gather. Then I face another direction of the map and same thing is happening. The node just vanish from the world and the minimap.

Is this intended like this ? do the nodes despawn after a set period of time or is it a bug.?

I have seen this as well. though I have found nodes actually there even after they disappeared from the map.