AI pathing doesn't recognize inaccessible navmesh area

[Belthan]

The setup is a building with two floors. First floor interior cell has doors to the second floor interior cell and to a ground-level door in the worldspace. Second floor interior cell has doors to first floor interior cell and a balcony in the worldspace (above the ground-level door). Navmesh works fine with followers and NPCs, with one annoying pathing glitch that occurs when an NPC is on the first floor and selects an AI package that requires them to be on the second floor. If they are closer to the door that leads directly to the second floor interior cell, they use it (which is the desired behavior). However, if they are closer to the door that leads to the worldspace, they use it (presumably because the pathing AI thinks they can get back into the second floor via the balcony door). However, there is no way to get to the balcony from the ground level, so they are stuck once they get outside.

 

There is a similar setup for Eulogy's Pad in Paradise falls, and comparing my balcony to Eulogy's balcony, I verified these similarities:

 

1) The balcony is a separate navmesh with no triangles connecting it to the ground-level navmesh.

2) The balcony navmesh edges are set to "ledge cover" and are NOT set to allow drop-downs.

 

So, if anybody has any insight into why the pathing for Eulogy's balcony works correctly and mine doesn't, it would be greatly appreciated.

 

As a footnote, I worked around the problem by creating two AI packages for each second floor package. One is the actual second floor package, and the other is a travel package (target is a marker near the door to the second floor) with the same conditions plus an additional condition that checks if they are on the first floor. It works, but it's a hack and it doubles the number of second floor packages for every NPC. I would much prefer to have the pathing AI simply recognize that you can't get to the balcony from ground level.