DELWYN wisp system bug?

A bunch of times (im in campaign) I get delwyn he says there is a wisp near...I hear the chase music but never actually see a wisp at all not even any enhanced mobs or wisp trails just...nothing

Still happening would be nice to get a wisp seeing how they have better loot

I think the biggest problem I have with wisps is that if you miss them then you may have already cleared out the mobs that it would have enhanced and/or possessed.

Wisps should spawn right at the start of the map, at least during the campaign. Otherwise you get things where you find the guy and the wisp too late in the map (maybe you took one of the other routes around the map and thus missed him entirely until the end...)