Masked material wont cast any baked shadows?

Currently i’m creating a material in my scene that needs a few holes in the ceiling.
However when i change my material to a “Masked” material (to enable to opacity slot) my material suddenly gets ignored by the lightbake.
Here you see the result:

I have already checked everything related to “2sided” rendering, though this did not make any difference.
Is there a proper way to do masked shaders that will actually cast shadows during lightbakes?

i also didn’t solve it to get shadows from only a double sided material on a boxbrush.
other than that, for rooms it is generally not a good idea to only have plane walls. give them a volume and model holes in it. this way you will have no problems

i never said i used box brushes, this is a mesh for the ceiling with some thickness to it, i need to have opacity masked on some areas to place some recessed features like light spots and other small details.
The holes dont need to be taken into account with baking, they just need to be there so that when a recessed light is placed in on the ceiling it doesnt clip.