Can you just try unplugging roughness and normal from the Landscape node (unless you already have done it)
Also, rather than creating several Layer node per roughness/normal/BC you might want to use MakeMaterialAttributes node which put the different setting per layer into one node and then you can blend them using the Layer node. You might even use your own way of blending using Sample node and HeightLerp
Here is how I did it:
https://i.imgur.com/imsV4Rem.png
https://i.imgur.com/8BWMiSrm.png
Do u know some kind of good tutorial on this materials guide or something because i am on learning stage now before this texture compile finish it will take a time
