What do you mean by "resume navigation in the cached" route? Are you referring to the saveRouteToCache and loadRouteFromCache APIs? (details here)
A rerouting call is triggered whenever the navigation engine detects that you are no longer following the route - i.e. you've been "matched" to a street/street segment that is not part of the original route. When recalculating the route, the same route settings used for the original route calculation are used (same end point, same routing profile, same via points) - the only difference being the start position (which is you current position).
In the scenario you have described on the forums you are calculating a route from a list of points and I'm assuming that you are starting to navigate on that particular route. Once you start moving I'm assuming that the navigation engine detects that you are not on the route (cannot really tell without looking at your input data) and triggers a rerouting call - at that time the routing engine attempts to create a route from your current position to the initial route and fails.
If you'd like to stop the rerouting logic, when you receive the call to onReRoutingStarted, call stopNavigation and trigger a route recalculation with your own routing engine.