Hi Daniele,
From the screenshots, it looks like you only did a single grid flight with the camera facing down. Also, in the thumbnails, the facade of the building is not clearly visible.
Because of its reflective roof and facade, this building is a more challenging object to scan, so more photos taken at shorter intervals between each other from various altitudes and angles would provide better results.
In this case, I would recommend at least a double grid flight with a camera set to an angle so more of the facade is visible. A circular point of interest flight or even a manual flight from a lower altitude and taking more photos of the facade would be even better.