Landscape HLODs have high Vertices amount

When i try to create Landscape HLODs, my HLODs will always have a super high resolution. This is slower that having the whole map loaded without HLODs.

I tried different HLOD settings and none of them make a difference.
What is the reason for this bug and how can i fix it?
Those are not solid planes, there are just so many Vertices that it appears as a solid plane.