Light bleeds through corners of the walls

What you do about this depends on your meshes and lighting scenario. Three recommendations off the top of my head:

  1. Don’t use single sided ( or no-depth ) meshes

  2. Use a dynamic skylight and get your shadows from mesh distance fields

  3. If you are using a dynamic directional light, make sure the parameter ‘dynamic shadow distance movable light’ is set to the default of 20000