I've just upgraded from an RTL515 to the Varia Vue 820. The behaviour with the swipe down control on an Edge 840 seems different though.
With the 515, I left it in Auto and if I was riding in a group I would press the button for Peloton. And then cancel override when I was on my own again and I would return to Auto mode.
With the new Varia, I now have to press the button twice. If you are in Auto and you press Peloton, it instead goes to Individual mode. You then have to press the Peloton button again.
Also, when you cancel override, it now stays in Individual mode and you have to manually return on Auto mode.
I notice that if you choose Flash as the override, it's stays in Auto mode. But if you choose Solid or Off, the behaviour is the same as Peloton.
Is anybody else seeing this behaviour? Is it a bug?