Why is the navigation mesh of platforms smaller on one side?

I am working on a 2D platformer and I am trying to use the navigation mesh to drive path finding.

My agents have a range of 8 and height of 16 (they are 16x16 pixels blocks basically, with a BoxCollider slammed on them).

It looks like the navigation mesh for the different platforms is being generated with one side being smaller than the other.

Window_e_Test2DPlatformer_-_Unreal_Editor

If you check the image above, you can see the green horizontal lines which are the debug mesh of the navigation mesh. The arrows are pointing to the sides where they are exactly 8 units smaller than expected and I can’t understand why.

Is there anyone who has an idea?