Lumen still darks below plane even with cast shadows disabled

[saMUcaZim]

i have a one sided plane,even if i disable cast shadows and AO lumen still will still dark below the plane,ive tried with a large cube and its the same.im using HWRT Lumen

here’s how it should be

[saMUcaZim]

also,i’m using single layer water shader model in the plane material