Sounds like you have not installed the maps locally? Use Garmin express for updates and when selecting the download ensure both PC and device are selected. I use Basecamp without any issues and it does offer many useful features. Must agree though the learning curve is steep before you start getting decent results.
Basecamp is dreadful, I think the web site is tyretotravel.com, it is easy and intuitive , head and shoulders better than basecamp.
Dreadful in terms of intuitive, agreed. Dreadful in terms of functionality, disagree. Having used it for a while now , I don't think I could go back. I've planned and completed some pretty complex routing using it and the Garmin and not had an issue yet. Only "gotcha" I have had is the need to make sure that if you update your maps that you run recalculate routes on anything you have previously planned BEFORE uploading it back to the satnav.