I have a mesh, a plane, and it is supposed to be a landscape with grass. It has some ups and downs not a flat plane. When adding the hair(grass). I did some weight paint to tell where the grass should grow. It seems to be more grass on lower parts of the mesh for some reason. The strange thing is that it looks fine in the viewport but not after rendering in Eevee. I have played around with the settings but can't find any solution. Would appreciate any help here.
This was all due to an unforgivable mistake of me. It is so embarrassing I can't even say what it was that caused this. Everything is working just fine. But as a remember to other: Never forget to disable a plane in render as well as in viewport if you don't use it. Maybe I should delete this whole post.