Vector direct in lines are reversed

Hello,
I used multiple horizontal (xy) planes to intersect with the surface A (random geometry but roughly lying vertically) to create lines on the surface A. Then I am trying to use “divide line” to generate points along the lines spaced 3 meters. However, the tangent direction along the lines are not consistent as shown in the picture. I have used “flip curve” by using a curve as a guide, but not working well. How can I make the lines’


tangent following a consistent pattern, for example, the arrow always points from left to right.

by your snapshots, the curves look near-planar, so you can flip curves according to their projections to a flat plane: