Weird material behavior

I’ve got this issue with my material.
Those textures are landscape layers, but the green one on the left side doesn’t behave as I want it to.
a) It merges color with the snow instead of behaving like the one on the right side
b) it has these pink-ish glitches that occur whenever two layers blend into each other.
Does someone have an idea why this happens?

Here are the layers BPs: blueprintUE | PasteBin For Unreal Engine 4

Interesting you say ‘pinkish’. If there’s something rainbow-colored going on, you’ll have a material error related to normals.

It could be using the wrong pin, or not processing normal textures in the same way as albedo. Quite hard to say exactly what…