Some cluster dont work correctly (FoliageTool)

Hi,

today i noticed the following problem, i painted gras on a landscape. But somehow, when i define a Cull disance i get something strange. The LODs of just some Cluster dont work correctly anymore ( the mesh dont switch into the LOD) and also the same clusters dont get culled away like all the other one.

I also tried to repaint it. It works after repainting more than 2 times but not always.

I post picture of this bellow.

I changed he Intensity of the Gras several times, maybe its because of this?