I am using the Stack Profile tool to create cross-profiles through a river (green lines).

For further analysis I need to determine the distance between the first vertex in the profile segment and the blue line that runs along the river length.
I have placed second vertices at these points, and was hoping it calculate values in the SEC_DIST column (Distance of the second vertex in the profile segment). However this is not the case.
So I was wondering is anyone knows what to change to actually get values in this column.
(Second figure shows locations of vertices)

(I am using ArcGIS Pro 3.2.0)