In the asset, the `fogBrightness` material property is set to `global`, which means a material property declaration isn't generated and the property's cannot be driven on a material instance (like `laser_001.mat`). The value used in the previews for the shader graph are just for preview. Shader Graph can't make assumptions about global properties, so that's something you'd have to drive via the `Shader.SetGlobal` scripting API.

There are a few ways to fix or improve this in the shader, but the simplest is to just use a clamp node on `fogBrightness` to ensure that the shader is always operating with an acceptable value range. It may be preferable to have the global be an offset or a modifier on a known good value instead. Whatever strategy you use, you will want to do so for any global properties you have in your shaders.