ARFoundation - Light inside LARGE prefab that gets placed, no shadows?!?

Hi guys

I have a rather large building about 300meter X 150meter and I drag the direct sunlight into it and made a prefab.

If I drag the prefab into the scene to test in editor, I can see the shadows of the sun. The directional light is on deafult settings.
I delete it from scene, but link same prefab into "Place on Plane" in AR Session Origin. Because the building is so big and I want to see it scaled on a table in front of me, I set the scale of the AR Session Origin to 200 on X,Y,Z.
I also set the Far Clipping Plane to 5000, otherwise half the building gets cut off.

Anyway, I build and deploy to android device, but there's no shadows at all. I tried setting things in Project settings > Quality to Ultra, but that makes no difference at all. I also set shadow distance from default 150 to 350, but that doesnt help (if I test the prefab in the editor, it does make the shadows look WORSE if I increase shadow distance)

Any ideas or suggestions?

FYI, I stick the light into the prefab, because later there will be a setting to adjust the time of day and then I just want to move the directional light in the prefab.

 

nevermind, my quality settings was too low