I recently purchased a vivosmart 3 last week. Everything was working fine until yesterday where my step count suddenly started showing over 900 million on the 'my day' screen in the app. If I select it to view details, the details UI is correct. The step count is also correct on the vivosmart 3.
I've tried restarting the app, re-synching, etc. The only thing I can think of is something is broken with the VO2 max. I did the VO2 test yesterday on the bracelet, and everything has been busted since then. I even tried doing another VO2 test today to see if it would fix it up, and it didn't. Also note that if I try to view the VO2 info in the app, the bottom of the UI simply states 'an error has occurred', so all signs are pointing to VO2 maybe being a problem here.
This appears to be an app or serverside issue, given the bracelet seems to show the right data. If I can't get this fixed I'm probably going to have to return the device :(