Android devices have a setting that sometimes blocks apps from updating correctly.
You can solve this by following these steps:
- Go to the settings of your Android device.
- Choose 'Cloud and accounts'.
- Continue with 'Backup and reset'.
- Scroll down until you see 'Automatic restore'.
- Turn the slider for this option OFF.
- Delete the Joyn app and install it again.
The problem should be solved now.