SetAreaCost is REALLY slow [UPDATED]

Hi everyone!

I’m trying to use NavMesh.SetAreaCost in a project where i want to change the calculation path in base of a choise of the user.
With a pression of a button in the UI the user can chose the path and after the choise i calculate the path.
The problem is when i call this function it will set the new value of the area afer more than 10 sec!
I really dont know why it’s soo slow!

public class PersonalizzaPercorso : MonoBehaviour
{
    public void PercorsoDisabili()
    {
          NavMesh.SetAreaCost(NavMesh.GetAreaFromName("Scale"), 10000);
    }

    public void PercorsoNoDisabili()
    {
        NavMesh.SetAreaCost(NavMesh.GetAreaFromName("Scale"), 1);
    }
}

It only a problem of visual updating in inspector! The value is updated with no issue in runtime