There was a bug in 5.4 and earlier where textures could be confused with what LOD to use. You would need to open the original non-virtual textures for the landscape and see if they appear to use a lower LOD. If so, you’ll need to regenerate the UUID or GUID as a workaround. If you’re using 5.5, this should be fixed. But if you upgraded from 5.4 or earlier, the effect from the bug can still remain. IOW, you won’t get new textures doing this, but existing textures can still have this effect.