Route selected for workout not followed/completed

Hi all,

Today I selected the Mountain route and started Emily’s Short mix work out.

At the end of the workout I carried on, to compete the route as I hadn’t completed it yet in Zwift.

I rode on, the route took me up the Radio Tower and then back down towards town. At each intersection the bike turned automatically.

After a while, I realised I had ridden over the course distance, and the route hadn’t shown as completed… then I realised the route I had ridden had deviated from the Mountain route once I was down to sea level.

I’m riding for fitness (and gaining elevation) so I’m not too bothered, but what went wrong?

I’m slowly ticking off the routes but don’t want this happening again on a longer route!