I've found the way.
1. Delete device from Garmin Connect
2. Check Garmin Connect online. Device is empty.
3. Add new device at the Garmin Connect. After that Don't change users setting.
4. Close Garmin Connect
5. Open garmin connect online (web)
6. change user setting and save.
7. open Garmin Connect and sync with vivofit. Setting will be apply.
Also I have noticed if you avoid going to the device settings in your mobile app the device settings page does not go bad on the Connect online. I noticed I could go into the mobile app and only set normal display settings. But when i tried to change during Activity display settings the app would crash and the settings were not accessible again after that on the mobile app or the web version online.
After performing the above steps member Mikhail_Ivanov listed and as long as I stay away from device settings in the mobile app everything stays working. At least this works until they patch this issue.
I agree with the above, if you remove your device from Garmin Connect (in my case Vivofit 3) restart the app and add a new device it will work, the Device Settings menu i mean.
The problem is that in this case everything gets reset, so you have to re-enter your values, your strafe, if you prefer metric etc etc.
But keep in mind, if you go into Device Settings and change a value, like the interface on your device everything will brake again.
So you have the choice, to have your device customised as you like but with one time deal since you won't be able to enter the Device Settings menu again, or
Be able to open and look, only look but not touch, the menu and keep your device generic as it comes.
Personally i did this 5-6 times until i get my vivofit 3 as i like and it did get me very frustrated but i had to do it since vivofit 3 only changes from the app, there is no buttons for it on the watch for that.
It got me thinking, maybe there is a reason why Garmin Connect is not bothering you to rate it on the app store like other apps do ;)
