Failed to make realistic landscape material with 4K and 8K textures...Where did I go wrong?

Hello all, I’m doing experiments on creating airport scene and I bought some textures from megascan.
But soon I found that my landscape material does not appears similar to that in their demo videos.

For example, after I fill the landscape with the forest grassland material, I can see a lot of tiling and still the terrain looks very flat and it even has a smooth reflecting and specular effect…


It does not look like that in their demo. (Although they have used weight map generated from world machine, but the areas of the same material still looks good)

It’s even not look like the texture’s demo picture.

I follow their tutorials and guidelines and set up material function first. This is pretty normal, multiply imported maps with scalar parameters.


And then link the material function to the landscape blend node…


The material ball does have some normal or bumpy look/
But the problem is I almost can’t see any bumps on the landscape which I applied the landscape blend material…
So I was wondering that is there a wrong connection of the spaghetti noodles or I missed something else?
Thanks…