faulknermano
You are right, it had miss something in my board system in squareTx layout.
In squareTx's '8 direction' mode, the grid will become an octangle, although it looks like a tetragon. So that it will have 8 edges, you need put a "wall" for diagonal side, currently.
I will try to solve it. Let me think....
[Edit]
You might try to turn the direction mode to 4 direction before requesting a path in slg_movement plugin.