Question

Why the new Map Data Version may alter routing results.

Answer

Even within maps from the same data provider, street segments can vary in length and orientation.
These changes usually result in minor differences that are often unnoticeable.
Switching from an old RouteOptimiser Version to xServer 2 may also mean a change in your map data provider, such as from TomTom to HERE, which can lead to noticeable result changes.