Dark landscape tiles

I need help with maybe my shadows? or lighting?
i use dynamic lighting, lumen, virtual shadow maps.
some landscape tiles just get very dark, also some of my materials got very dark, the materials become normal looking if i remove the normal-map from them, but landscape layers wont.
I have 6 landscape layers, and one of them makes the tiles normal-looking, if i paint it on them, even a little bit, just looking for “real problem”, because some of my materials have the same problem, is there some way to troubleshoot / find whats the cause, or will i start to remove normal maps, and paint my landscape all over

I have rebuilt everything, my landscape has no HLODs, i have removed everything and built lighting again and again from scratch.