Just noticed that Round Trip Course Navigation is only available for Run, Bike which seems like a strange limitation...
Why is this feature not available for Walk and Hike for example? On searching I came across a F5 post commenting on the same, you'd think in 4 years this feature would have been opened up...
forums.garmin.com/.../round-trip-course---only-for-running-and-bicycling-not-walking