Another wierd error with landscape layer blends

Hey guys,

When I try to get a 3rd layer involved in the material landscape this is what happens:

8d714747085e335ecabf913870bc596485d1099d.jpeg

I’ve set the 3 layers blends based on height( sry for the mess) :

8d52a1da1117415bf579e34a65f02d1387234848.jpeg

It works fine with just 2 inputs from each layer ( such base color + roughness or base color + normal or roughness + normal) but not when I try to use all 3 of them.

Any suggestions?