UV map doesn't work and is affected by normals

I’m trying to rework an old project but after recreating the (admittedly atrocious) geometry and creating the walls, the uv unwrap doesn’t work at all. In this video you see me cube project the wall faces, rotate them with Correct Face Attributes turned off and on, and changing the normals with ALT+L. Weirdly enough, that causes the texture to kind of show, but it obviously is not the full solution. https://streamable.com/wv2qms

It was set to box instead of flat.