Landscape material not working: material function x layer blend

I made a landscape material where i combine 4 material function instances with a layer blend so I can paint those different instances on my landscape.
But for some reason it doesn’t work.
The end result is that every layer has exactly the same look (sand), but the textures in my material function are different (sand, sand pebbles, rock, stone) so this shouldn’t be possible.
When i test the layer blend with vector 3 colors they work and the material functions themselves work as well, just when I combine the material functions with the layer blending it breaks.
any suggestions?

I created one material with one material fucntion to input all the data I previously handled by using the material function instances and this works, but it’s less nice obviously so still wondering why the materal function instances don’t work.
The material function i use now is exactly the same as before, i just swapped out all the parameters by function inputs which I feed inside the material