Shadows through masked material problem.

Shadows through masked material problem. I have a poly plane with a material that is masked… a spot light aims through it to cast shadows… works fine with dynamic light, but building as a static mesh gives odd terrible results. See the screenshots… what is wrong here?

Here is what happens when i lower the source radius… so i can make the mask sharper except the shadow on the edges doesnt cast quite right… u see it still is a round circle with the spotlight… even though it should be boxed out because the spot light extends past the masked invisible part… so what gives?653cc78319dd8c1cc7ecf458a0692f9cfa7e40e7.jpeg

What’s the floor’s lightmap resolution? Did you build lighting with production quality settings or just preview?