Profile Intersection Point Pulling Elevation from Template Drop

I am attempting to profile the gutter line for an intersection return. One one end of the return I want the profile to match the existing gutter line, and on the other end of the return I want the profile to match the proposed gutter line from my corridor model. To snap to the existing gutter line I created a surface profile along the return. To snap to the proposed gutter line I used the Profile Intersection Point command. I want my profile to connect the existing ground surface on one end of the profile to the point on the other.

The problem is that the point generated from the Profile Intersection Point command is apparently grabbing the elevation from the wrong location along my corridor. I have a template drop on each side of the intersection, and the command appears to be grabbing the elevation from the end point of the gutter line at the wrong template drop.

The issue appears related to the tiniest of gaps between the arc and my corridor:

And if I extend my template drop well past the arc, the elevation self-corrects:

But if I snap the template drop back to the endpoint of the arc, the issue returns:

Does anyone know a good fix for this?

Thanks in advance!