I’m using a Shadow Caster 2D on the “Buildings” layer of my tilemap.
It works great and casts shadows onto the wall correctly, while still receiving shadows like expected.
Though I cant figure out how to make a Light 2D inside the shadow caster cast light outside of the shadow caster? For Example a light on a wall is supposed to also illuminate the floor infront (=under) the wall.
Below is a representation, the Shadow Caster 2D Component and the Light 2D Component.

As I understand it, the light is blocked by colliders in the shaow caster 2D. your grey box seems to have a collider, which creates a shadow all around that box. as I understand it the only way is to remove the collider from the box, or to set the shadow caster to “sprite bound” (I don’t remember the exact name of the option, it is the third from the top)
the only way i can think of is if you would model tha actual room underneath first. then put the light in
add a second sprite on top and make it ignore the lighting by setting it to another light layer. also the roof object should have no shadow caster attached. so the light can “slip” beneath it.