Misplaced light source on custom part

[JoeDeertay]

Hello all. I just started getting into modeling parts with Blender and Unity so I could basically "weld" subassemblies together to reduce part count (I know there are already part welding mods, but I figured this would be a perfect way to start learning), and it eventually got into making new parts for specific builds. First one I made myself is a 5.5m payload bay with sliding doors to put on a Starship, and it has the same materials/textures as the silver fairing to match the rest of the ship. Everything looks and works great except for the light source being 180 degrees off axis from the rest of the parts somehow, as you can see in the VAB screenshot below based on the reflections from the part and fairings. This also happens on the launchpad, and if I time warp I can clearly see the light is hitting the part in the opposite direction of the sun as it moves.

I've tried rotating the model all kinds of ways in Blender and Unity and wherever the light source is doesn't seem to ever move, so I'm not sure how to fix it. Anyone have any ideas? If you need any more info or screenshots let me know and I'll post it. Thank you so much!