Weird shadows on distant grass Foliage using Raytracing and Megascan?

Hi
Is it normal to have weird shadows on the most distant LoDs of the foliage (Landscape Grass Type) when Raytracing Shadows from my Directional Lights are ON?
I am using Megascan assets. Is it the Billboard LoD causing problems?
Any way to solve it and keep Raytracing on?

Thanks