Can't paint different layer on my landscape

Hi everyone, I a have create a landscape wich I did sculpt, an now I want to paint 3 texture on it, so I have create a master material with all the parameters I want and separate them into different layers, in my landscape menu I can see all my layer and in my instance I can tweak the parameters. The probleme is that when I paint, nothing append, absolutely nothing, I have follow a few tutorials to fix my issue but nothing change, I have tried to keep the output node and to separate my layer by channel (1 node landscape layer blend for the albedo, 1 for the roughness etc…), I also tried differents ways but I can’t find my problem… Maybe it’s beceaus I use a parameter node for my color instead a classic map but I don’t know. If someone can help me it would be great please.

Have a nice day everyone.