Going into cave

[Skalikas 8]

Working on a quest: http://www.wowhead.com/quest=11276

The quest is a simple PickUp -> TurnIn quest.

Location: Outside and inside the cave near Utgarde Keep (Howling Fjord).

I'm having a problem with movement from the quest pickup location to quest turn in location (underground). Bot simply goes to the coordinates overground and doesn't try to enter the cave to go underground.

I tried to force it to first go into the entrance of the cave before trying to turn in, but Bot still simply goes outside and to the location overground. I also tried to move into the cave through multiple 'GoToTask.ToPosition', yet when it encounters first coordinates that are 'too deep' it leaves the cave and tries to reach that position overground.