@Anzak: Even though the default for an empty tiles edge cost is set to 1 in all directions, it is not automatically included in the EdgeArray when added to the grid during runtime. You will more than likely need to add the new ‘spawned’ tile index and it’s edge costs to the EdgeArray. Anytime you make an update to a tile (add or remove a wall, etc) you will have to update the EdgeArray as it directly effects the Grid Managers ‘Can Move to Array’, which is created with the Pathfinding function.
Edit: As a quick pass for creating a little function that did it for you, it could look something like this;
This will accept your new or current tile that you are attempting to add to the EdgeArray and then include it’s Edge Cost and Index of that tile if it is a valid Tile_Parent (or child).