One part of the building ("Building_p2") is not in the family, maybe that's the reason?
Also, since your game is grid-based and the character is walking from cell to cell, I recommend you use TileMap objects. You can build your entire map with a single or several TileMaps, instead of using hundreds of sprites. Or, you can continue using sprites, but add an invisible TileMap and set tiles where you want your obstacles to be. This way you can easily determine if your character can move in any direction by checking if the tile in that direction is set or not.
Here is an example (it uses MoveTo addon, but should give you the idea):