Changing normal map intensity

Hello,
if I am not complitly wrong one used to be able to change the normal map intensity in the Standart shader in the Unity UI right next to the imput field for the normal map.

But the intensity doesn’t change no matter how high or low I put the number. One was even able to invert the normal map that way.

Secondary normal map doesn’t show at all.

I am using 5.6.1f1

Thank You!

Is the texture marked as a normal map? It could be a standard texture and therefore not working.