Landscape Material Normal Maps

Hi, I’m trying to make a Landscape material with automated blend between grass and cliffs and a painted layer for the beach areas. It works perfectly without normal maps, but as soon as I add them and then paint it, the Landscape components with it stop showing up. It also works if I plug in a flat 0,0,1 vector.

I’ve tried with several blending methods and functions, but every time they lead to the same result. I’m making the materials with functions and then blending the material attributes with a CheapContrast function. Currently I’m lerping the Normal Maps seperately so I can see what is going on. What am I doing wrong here?