Maximum size for collider to block flare??

Having real trouble with large object colliders. It seems a sphere collider with a diameter of 1000 units blocks lens flares perfectly, but a sphere collider with a diameter of 10000 units does not block flares at all.

Can anyone tell me more about this limitation? Is there a work around? I’m working on a planetary scale and everything is working great, apart from this bug.

Hi,
I have the same problem, did you by any chance figure it out ?