Roadway designer - The controlled (constrained) point move from original place of parent point

Question

In template Point T2-U2 is controled from T2-D2 by slope and project to surface up: 
 
 Point T2-D2 is controled by ditch, and this point moves down and left. 
 Result: 
 
 But instead T2-U2 to chase T2-D2, the point acts as the parent point stayed at the same location in template. In this example only when solution for project to surface is not active: 
 
 This appeared many times in "healthy" conditions. And mostly from Slope and Project To Surface controls. 
 Is there some restrictions to not use Point Control of points that is used for Constrains of other points, or this is some kind of bug ?

jpln · Accepted Answer

Hi Aleksandar, 
I am not sure to have well understood the issue. But if the point doesn't move as expected it is maybe because the constraint is not solved. In this case T2-U2 is defined by "project to surface" and "slope". If prohect to surface is not resolved (surface doesn't exist, or is below the point), then the point is undertermined so keep its original location in the Template.