The tiles are children of a GameObject with a NavMeshSurface component. Everytime a tile is placed, BuildNavMesh is called, but it doesn't seem to update everything, even when making the voxel size smaller. Each tile is 1x1 unit. It will rarely put a mesh on a 1x1 lone tile, and you can see at the beginning, it ALWAYS waits until 3 or more tiles are down before generating. Edit: Scaling the tile up to 2x2 makes it generate every time, but why can't it do 1x1?