Shadows on grass raytraced

Hi All, so I’ve tried to troubleshoot this with degrees of success but I’m currently stumped on this. I am trying to get shadow to cast over my scattered grass. currently it renders correctly in my normal static camera views note how there is clearly shaded and lit grass -

However it all goes wrong when I try to use my aerial cameras -

However it looks correct in editor -

I’m scattering multiple clumps of planes with a alpha masked grass, the clump has planes facing all directions so it’s covering all angles.

detailed lighting looks correct -

it appears to be an issue also in the 360 renders i’m outputting - It feels like it’s a limit somewhere as aerials show large amounts of scene as do a 360 encompasses the entire area around it - just no idea which limit it’s reaching!