I've been playing with this and trying to figure out the logic in what is preventing all of the routes from properly being selectable in the Drive Menu.
Using the NERW as a test route, I can work around the issue, but still don't understand why it works.
Basically if I go and edit RouteProperties.xml and add a space as follows
<Localisation-cUserLocalisedString>
<English d:type="cDeltaString"> North Eastern - PA Div</English>
It behaves as expected, and the route appears properly in the Build menu and I can select and filter scenarios (this also works with Workshop routes).
It's weird however, as I've checked other routes that are displaying properly, and there is no additional spacing required in the string.