OK, if there is no split you can try to search for the part in the feature manager under the folder 'Route Parts' > delete it and than do right click on the sub-assembly > 'Edit Route' > exit the route sketch. At this point the body from the part recreates and see what you end-up with.
Can you edit the route and see if the spline path is split at the point where the route appears disjoint?
The spline path has to be one single spline. I have tried to split the a spline and got the same visual effect after exit route edit.