Hi - Thanks that is useful to know
At present the routing service used by the Auto-Plot feature on the Paths map assumes that bridleways are not suitable for cycling unless the bridleway is explicity tagged as suitable for cycling on the OSM database. This is an issue that our routing provider is aware of and will be addresssing at some point. In meantime you can make changes to the Paths map yourself if you like, to tag any bridleway as suitable for cycling - further details can be found in our forum topic on Making Changes to the Paths Map.
Off road paths that are for cycle use (ie. bridleways in UK) are shown and treated the same as footpaths on map. To create a route therefore, i have to use the map in conjunction with a full OS Map.
The route plotter will then often not select these bridleways, forcing the route to have to be mapped by turning off the auto-router and selecting manual waypoints.