Hey guys i find it really not like confusing, but bad in general that you call Shader - Material, and Material instance - Material.
Because that confuses a lot, if you work with root material, it should be called a SHADER thats what it is basically you use nodes,
to compile that into a shader, and AFTER you crate a material from that shader which is called Material Instance in UE.
More than that - if you look at a folder filled with materials(shaders) and material instances(materials) there is not way to distinguish those
://i.imgur/SUTDvQa.png
so they clearly need a special icon that shows they are different.
Like rly, shader is shader, and material is basically a wrapper for that shader dictating it which textures etc to use,
like that’s my advice - change that.