Unable to upgrade firmware on Vidonn X6 bracelet I bought myself a Vidonn X6 sports band, and am having issues upgrading the firmware.

The new version released last week of the app on the Android adds support for the X6, and is offering a newer firmware version for my sports band. When I try to install it, the band's face shows up 'Up' arrow (taking on an upgrade), and stays for approximately one minute, while the phone stays on the 'Upgrading' screen in the app.

After a minute, the arrow disappears off the band, and the Bluetooth settings screen comes on. I have tried:


waiting, 
backing out to the app, and 
disabling the Wifi so Vidonn asks to turn it on.


None of these seem to finish the upgrade, and in all instances, I have to pair the sports band back to my phone. The battery was charged up to 100%, so I know it's not a power issue.

What more can I try to get the newer firmware installed?
Got the same issue on my OnePlus, unable to upgrade firmware, my smartband had some issues (screen not working). After long search, found it : uninstall vidonn2.0 app , download vidonn tool.apk and firmware https://goo.gl/BZYGsQ (read the text file) then install it, reboot phone, launch Vidonn tool then flash firmware. You can also try to flash the firmware in the Vidonn2.0 directory on the phone.