Hello!
I've had this Vivosport not even 5 days. Yesterday it started going crazy. I'd be not even touching the screen but it would be cycling through the menus and changing settings all on its own. Like, several different settings, and I'd just watch it do this for a solid minute before it would stop. It changed the autolock feature on its own, the vibration, then tried to start a run. It kept going back and forth through the menus constantly until it stopped at the "double tap" to start activity. I then try to go through the screens on my own and it would take over again and go crazy. It did this for a couple hours.
At some point it stopped, but then in the middle of the night last night I was wearing it and it woke me up, it just kept vibrating and going through menus again. I switched it to be auto-lock always on, and not sure what happened after that. I got back to sleep but I woke to the battery level at 20% (it was JUST charged to full 1 hour before bed!
thinking of returning it already...