1. Open attached project
2. Open test2 scene
3. Enter play mode
4. Observe the Character objects (spheres) moving
Expected result: They walk around built-in layer 0 (Walkable)
Actual result: They walk through it (one of them does it quite strangely too, going for the corner first)

The project contains a simple scene, with cubes making up for the majority of "terrain", each of them set to a certain layer of navigation. In Update() method, we're calling NavmeshAgent.SetAreaCost(0,50), to set the default layers cost to 50