UE5.3 lumen | Transparent glass windows blocks light, making the interior space black


As you can see I have a simple room, made with solid walls, floors and ceiling

The window mesh, both the frame and the glass panel is solid

When I import it to UE5.3, add sunlight, skylight, sky atmosphere, select 2 window meshes and tick “shadow indirect only”

But the transparent window still blocks light, you can see it when I toggle the visiblity of the window.

Is there anyway to make the window behave like the real world?