Seems if i try to put a point on a "tangency"

point choices the vertical line and there is no real contact tangency?
Does this normal ?
it's a mega super ultra zoom :)
The green arc never touch the black vertical... and don't overpass it, (that is good :)

https://moiscript.weebly.com/uploads/3/9/3/8/3938813/arc_tangency.3dm