MeshDataTool does not calculate all Normals correctly

**Your Godot version:**
4.2 Mono
**Issue description:**
I followed the tutorials on generating an [ArrayMesh](https://docs.godotengine.org/en/stable/tutorials/3d/procedural_geometry/arraymesh.html#doc-arraymesh) and using [MeshDataTool](https://docs.godotengine.org/en/stable/tutorials/3d/procedural_geometry/meshdatatool.html) to update the normals of a displaced mesh. My understanding is that MeshDataTool should help in calculating normals of a modified mesh. However, it seems that even in this tutorial demo there is a visible seam that extends from the positive y-axis to the negative y-axis, see picture attached. Display Wireframe and Display Unshaded do not show any issues so I figured the normals along that seem are off.
Any ideas on how to fix this issue?

Is this even a documentation issue or more of a godot engine issue?


**URL to the documentation page:**
[ArrayMesh](https://docs.godotengine.org/en/stable/tutorials/3d/procedural_geometry/arraymesh.html#doc-arraymesh)
[MeshDataTool](https://docs.godotengine.org/en/stable/tutorials/3d/procedural_geometry/meshdatatool.html)