LunchBox Shortest Walk - assessed point location

While playing with Curves.ShortestWalk node I got this unexpected outcome : the shortest path is not the shortest.
Blue lines represent CurveNetwork. P1 is a point to be assessed for shortest distance to Exit.
Depending on how far is this point from the CurveNetwork line, the outcome is different.
Below is the case where distance to vertical line is shorter than to diagonal one. Green is the calculation outcome, definitely not as expected.
It seems that x distance is calculated first and this drives the preferred curve network line. Is there any way to alter this ?