Yes Mark, I'm afraid sometimes the routing service we use for OSM maps doesn't have all the paths shown on the map, so occasionally you will need to plot on these paths with the Auto-Plot swtich off. This is mainly a timing issue with different datasets being updated at different times.
I've noticed that when I switch to the OSM outdoor maps option I see a lot more "paths" such as parking lot paths, but the auto-pilot will not follow them. However if I am in Google Street Maps, it will.
The Paths map uses open source data from OpenStreetMap. If you want to add to the Paths map you can contribute to the base map data if you like - this is the link for this: Contribute to OpenStreetMap Data
The other maos types use data from Google. You can give feedback to Google on this by clicking the "Report a map error" link in the bottom right corner of the map.
We cycle paths that are not on plotaroute.com. How can I edit the map to add these paths?