Problem with Spot Light and PSX shader!

When I started using the PSX shader (GitHub - dsoft20/psx_retroshader: Shader that "emulates" the rendering style of ps1) I started having problems with Spot Light! It stopped reproducing the light, but when I use Point Light, then everything is fine. Wall Material Shader - vertexlit

This is a vertex-lit shader. As such, all lighting applies only directly to vertices. In this case, it looks like you have a very low poly mesh and a very narrow spotlight, meaning the spotlight is most likely missing the meshes’ vertices which would skip lighting. To fix this you can use a higher poly mesh or increase the spotlight’s angle.