Foliage black with path tracing and direct light

I have 24 posts in this forum and 0 replies…anyway I 'l try again (unreal support is awful…):
path tracing with direct light is getting some foliage fully black (except where it is in shadow area), see image … if I disable direct light it is working niely with HDR light only.

Any advice ? (aahhahahaha!!! I know no one will give a reply as usual…)