From licensee:
The height of Nanite rendered landscape does not match the height of non-nanite landscape. The error gets worse if you increase the Z Scale of the landscape actor.
Our project recently upgraded from UE5.1 to UE5.2. We quickly noticed a problem with small grass and foliage meshes either floating or positioned under the landscape, by around 10 cms in places. Enough to be problematic with small detailed foliage meshes. Our character's feet were similarly seen to sit above or below the Nanite enabled landscape. Entering the console command 'landscape.RenderNanite 0' immediately gets everything to appear sitting perfectly on the landscape.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-198318 in the post.