WorldAlignedTexture WorldPosition. Is it broken or am I doing something wrong ?

Hello,

I, trying to make a mask for my terrain object using the WorldAlignedTexture Node. Basically it looks like this.
I´m nearly there. But there is that visible seam I want to get rid of.

s_UE4_problem_02.jpg

According to the Docs. “WorldPosition (Vector3) Provides an offset for the start point of the texture in 3D world space.”
So it sounds to me like it ´s exactly what I´m looking for to shift the texture so the seems is out of the way.
I added a Constant3Vector to the WorldPosition Parameter. But as soon as it´s there the whole effect dissapears.
No matter what Values I type in. Any help is much appreciated. Also if someone knows a way to get that desired effect
with some other way.
Below two other screenshots of the Material when it´s not working.


Think you need Absolute World position node , look at ~4:30 can give you a hint Adding Wind to Grass in Unreal Engine 4 - World Position Offset Tutorial - YouTube

Plug actual normal and position to that node or result will be garbage.