Directional light leaking into indoor areas

Hi. I have an issue where light from a directional light is seeping through the edges of indoor meshes.

The meshes were constructed with probuilder, and the mesh rendereds for indoor areas have their shadow types set to Two-Sided. The issue still persists even if I zero the bias and normal-bias of the directional light. Setting the mesh shading to smooth rather than flat fixes some of the leaks, however this is not an ideal solution as it creates smooth shading on meshes that should have flat shading. Any help resolving this issue would be greatly appreciated. Thank you.