Question Normals look noisy under some lighting angles

Hi everyone,
I am a 3d artist and I am fairly new to shader graph and unity.
I made my first shader for a terrain (needs to be a 3D mesh) that uses vertex color information to modulate between different textures.
Now the problem I am having is under some light angles the normals get very extreme shadowing, I think it may be because of my shader because when I assign a standard material with the same textures I don't seem to have the problem. The textures I use are from megascans with their Y channel inverted, currently jpegs. The textures are set as normal map under texture type and are defined as such in the shader sampler. I would really appreciate it if someone has an idea as to what could be wrong. I'm including screenshots of the problem and relevant shader graph information.

 

Ok I think I solved it and it wasn't the shader after all. It seems that normals on the geometry might have gotten corrupted after moving it between unity and 3ds max in the process of vertex painting and fixing other things. I had to flip normals in 3ds max and then flip them back and that seemed to fix the problem.