Surface Direction and Normals Correct (I think) But Texture Mapping is Wonky

I am trying to join these surfaces for my backdrop and then practicing a gradient color/texture map on the surface, but it’s not mapping correctly, despite all normals and directions matching (apparently). What’s the deal?

Hello - set a planar mapping from the front for the entire thing - ApplyPlanarMapping
Polysurface faces each get their own UV mapped texture portion with default surface mapping.