Volumetric light/Light Propagation bleeding through landscape... unless landscape is selected

I’m experiencing this strange behaviour with volumetric lighting and dynamic GI bleeding through the landscape, unless I directly select the landscape in the editor. The map is supposed to use a dynamic tod system, so baking is not an option here. So far I’ve set the landscape’s lighting and lightmass to two-sided, this has worked for some objects that the GI/volumefog was bleeding through, but sadly not the landscape itself. Oddly enough, lighting is proper when I have the landscape selected in the editor. Any ideas?