When PackedLevelActor is placed across navtiles, navmesh is incorrectly split and generated in navtiles

When creating a PackedLevelActor by packing multiple StaticMesh, the navmesh isn't generated correctly on top of it. In detail, navmesh is generated by splitting on navtiles. This is probably due to the fact that the navmesh can be generated correctly without packing. 

1. Create a new map
2. Add NavmeshBoundsVolume on the level
3. Add 2 cubes on the level
4. Select cubes and select "Level->CreatePackedLevelActor"
   Then, checking the "Draw Tile Bounds" checkbox in RecastNavmesh, the tile borders can be seen and the navmesh will not be generated in those areas.